SSDs / Compare
Fanxiang S500 Pro vs Sandisk Optimus GX PRO 850X
Product A: Fanxiang
27 of 63 known
Change Fanxiang S500 Pro
Product B: Sandisk
48 of 63 known
Change Sandisk Optimus GX PRO 850X
40 of 55 fields differ
- 17 different values
- 23 known for one only
- 6 the same
- 9 missing for both
Biggest differences
Each bar uses the scale of all 84 SSDs.
- Write speedA: 3,000MB/sB: 6,600MB/sSandisk is 3,600 MB/s higher.
- Read speedA: 3,500MB/sB: 7,300MB/sSandisk is 3,800 MB/s higher.
All 63 fields
Every value links to where we found it.


General
6 of 9 differ
Series
Not available
Model numbers
Not available
SDSP81100TAN-000E0, SDSP81100TAN, WDS100T2X0E, SDSP81200TAN-000E0, SDSP81200TAN, WDS200T2X0E, SDSP81400TAN-000E0, SDSP81400TAN, WDS400T2X0E, SDSP81800TAN-000E0, SDSP81800TAN, WDS800T2X0E, SDSP81100TAH-000E0, SDSP81100TAH, WDS100T2XHE, SDSP81200TAH-000E0, SDSP81200TAH, WDS200T2XHE, SDSP81400TAH-000E0, SDSP81400TAH, WDS400T2XHE, SDSP81800TAH-000E0, SDSP81800TAH, WDS800T2XHE1Maker spec sheet (PDF)documents.sandisk.com/content/dam/asset-library/en_us/assets/public/sandisk/product/internal-drives/sandisk-optimus-gx-pro/data-sheet-optimus-gx-pro-850x-internal-ssd.pdfRead 14 October 2026Bare drive models SDSP81100TAN, SDSP81200TAN, SDSP81400TAN and SDSP81800TAN2Maker spec sheet (PDF)documents.sandisk.com/content/dam/asset-library/en_us/assets/public/sandisk/product/internal-drives/sandisk-optimus-gx-pro/data-sheet-optimus-gx-pro-850x-internal-heatsink-ssd.pdfRead 14 October 2026Heatsink models SDSP81100TAH, SDSP81200TAH, SDSP81400TAH and SDSP81800TAH3Maker spec sheet (PDF)documents.sandisk.com/content/dam/asset-library/en_us/assets/public/sandisk/product/internal-drives/wd-black-ssd/data-sheet-wd-black-sn850x-nvme-ssd.pdfRead 14 October 2026Earlier WD_BLACK SN850X model numbers: WDS100T2X0E, WDS200T2X0E, WDS400T2X0E, WDS800T2X0E (without heatsink) and WDS100T2XHE, WDS200T2XHE, WDS400T2XHE, WDS800T2XHE (with heatsink). Same hardware under the old name. Sandisk's own page lists the Optimus numbers4Maker product pagesandisk.com/products/ssd/internal-ssd/sandisk-optimus-gx-pro-850x-internal-nvme-ssdRead 14 October 2026SKUs SDSP81100TAN-000E0, SDSP81200TAN-000E0, SDSP81400TAN-000E0, SDSP81800TAN-000E0 and SDSP81100TAH-000E0, SDSP81200TAH-000E0, SDSP81400TAH-000E0, SDSP81800TAH-000E0
GTIN / EAN
792288883771, 792288883788, 792288883795, 7922888838012Maker product pagefanxiangssd.com/products/internal-solid-state-drive-fanxiang-s500-nvme-ssd-pcle.jsonRead 15 October 2026Store product feed barcodes: 792288883771 (256GB), 792288883788 (512GB), 792288883795 (1TB), 792288883801 (2TB). All four are valid UPC-A codes
619659231972, 619659231965, 619659231958, 619659231941, 619659232016, 619659232009, 619659231996, 6196592319894Maker product pagesandisk.com/products/ssd/internal-ssd/sandisk-optimus-gx-pro-850x-internal-nvme-ssdRead 14 October 2026UPC in the page data: 619659231972 (1TB), 619659231965 (2TB), 619659231958 (4TB), 619659231941 (8TB) without heatsink. 619659232016 (1TB), 619659232009 (2TB), 619659231996 (4TB), 619659231989 (8TB) with heatsink
Announced
Not available
Status
Predecessor
Not available
Not available
Successor
Not available
Not available
Launch price (US)
Not available
$289.995Press articlestoragereview.com/news/western-digital-announces-new-wd_black-gaming-ssdsRead 14 October 2026Western Digital's release says 1TB, 2TB and 4TB start at $189.99 (U.S. MSRP). Launch-day coverage and the Tom's Hardware review table list $159.99 for 1TB, so the May figure is not stored6Press articlepcgamesn.com/wd/black-sn850x-release-priceRead 14 October 2026Launches at $159.99 for the starting model (1TB), US7Reviewtomshardware.com/reviews/wd-black-sn850x-ssd-review-back-in-blackRead 14 October 2026Specifications table pricing, US, without and with heatsink: 1TB $159.99 / $179.99, 2TB $289.99 / $309.99, 4TB $699.99. Review text calls it the launch pricing and MSRP. 4TB had no heatsink version at launch9Reviewtomshardware.com/pc-components/ssds/wd-black-sn850x-8tb-ssd-review-the-no-compromise-8tb-championRead 14 October 2026Specifications table pricing for 8TB: $849.99 without and $899.99 with heatsink, US. Review published 16 October 202414Press articleguru3d.com/story/western-digital-releases-8tb-variant-of-wd-black-sn850x-ssd-atRead 14 October 20268TB launch coverage dated 16 July 2024: $849 without a heatsink (WDS800T2X0E) and $899 with a PS5-compatible heatsink (WDS800T2XHE). IT Home reports $849.99 and $50 more for the heatsink
Launch price (EU)
Not available
From €539.991Maker spec sheet (PDF)documents.sandisk.com/content/dam/asset-library/en_us/assets/public/sandisk/product/internal-drives/sandisk-optimus-gx-pro/data-sheet-optimus-gx-pro-850x-internal-ssd.pdfRead 14 October 20262Maker spec sheet (PDF)documents.sandisk.com/content/dam/asset-library/en_us/assets/public/sandisk/product/internal-drives/sandisk-optimus-gx-pro/data-sheet-optimus-gx-pro-850x-internal-heatsink-ssd.pdfRead 14 October 20263Maker spec sheet (PDF)documents.sandisk.com/content/dam/asset-library/en_us/assets/public/sandisk/product/internal-drives/wd-black-ssd/data-sheet-wd-black-sn850x-nvme-ssd.pdfRead 14 October 20264Maker product pagesandisk.com/products/ssd/internal-ssd/sandisk-optimus-gx-pro-850x-internal-nvme-ssdRead 14 October 20267Reviewtomshardware.com/reviews/wd-black-sn850x-ssd-review-back-in-blackRead 14 October 20269Reviewtomshardware.com/pc-components/ssds/wd-black-sn850x-8tb-ssd-review-the-no-compromise-8tb-championRead 14 October 202610Reviewtomshardware.com/pc-components/ssds/wd-black-sn850x-8tb-ssd-review-the-no-compromise-8tb-champion/2Read 14 October 202611Reviewkitguru.net/components/ssd-drives/simon-crisp/wd-black-sn850x-with-heatsink-2tb-ssd-review/all/1Read 14 October 202614Press articleguru3d.com/story/western-digital-releases-8tb-variant-of-wd-black-sn850x-ssd-atRead 14 October 202615Press articlechannelpartner.de/article/3902358/western-digital-verdoppelt-kapazitaet-seiner-gaming-ssds.htmlRead 14 October 2026
Markets
Not available
Not available
Form factor
M.2 22801Maker spec sheet (PDF)documents.sandisk.com/content/dam/asset-library/en_us/assets/public/sandisk/product/internal-drives/sandisk-optimus-gx-pro/data-sheet-optimus-gx-pro-850x-internal-ssd.pdfRead 14 October 2026Form factor row reads M.2 2280-S3-M for 1TB and 2TB and M.2 2280-D5-M for 4TB and 8TB4Maker product pagesandisk.com/products/ssd/internal-ssd/sandisk-optimus-gx-pro-850x-internal-nvme-ssdRead 14 October 2026Form Factor reads M.2 2280 S3-M for 1TB and 2TB and M.2 2280 D5-M for 4TB and 8TB
Capacity
1 TB, 2 TB, 4 TB, 8 TB1Maker spec sheet (PDF)documents.sandisk.com/content/dam/asset-library/en_us/assets/public/sandisk/product/internal-drives/sandisk-optimus-gx-pro/data-sheet-optimus-gx-pro-850x-internal-ssd.pdfRead 14 October 20261GB = 1 billion bytes and 1TB = 1 trillion bytes. Capacities 1TB, 2TB, 4TB and 8TB4Maker product pagesandisk.com/products/ssd/internal-ssd/sandisk-optimus-gx-pro-850x-internal-nvme-ssdRead 14 October 20261TB, 2TB, 4TB, 8TB
Interface
1 of 5 differ
Interface
PCIe generation
31Maker product pagefanxiangssd.com/products/internal-solid-state-drive-fanxiang-s500-nvme-ssd-pcleRead 15 October 2026Product label and tags read PCIe Gen3 x46Owner's manualixbt.com/live/platform/obzor-kitayskogo-m2-nvme-nakopitelya-fanxiang-s500pro-chestnye-3500-mb-s-i-pcie30x4.htmlRead 15 October 2026Same leaflet table: Interface PCIe Gen 3x4
PCIe lanes
41Maker product pagefanxiangssd.com/products/internal-solid-state-drive-fanxiang-s500-nvme-ssd-pcleRead 15 October 2026Product label and tags read PCIe Gen3 x46Owner's manualixbt.com/live/platform/obzor-kitayskogo-m2-nvme-nakopitelya-fanxiang-s500pro-chestnye-3500-mb-s-i-pcie30x4.htmlRead 15 October 2026Same leaflet table: Interface PCIe Gen 3x4
NVMe version
1.44Retailer pageamazon.com/dp/B0B55TQMFJRead 15 October 2026Current US 1TB listing, Connectivity Technology reads PCIe Gen3x4 NVMe1.4. The 2022 archived listing of the same product says NVMe 1.3 in its table and bullet, so Fanxiang's listings conflict. The newer 1.4 matches the version the drive reports itself in CrystalDiskInfo (see the iXBT review)5Reviewixbt.com/live/platform/obzor-kitayskogo-m2-nvme-nakopitelya-fanxiang-s500pro-chestnye-3500-mb-s-i-pcie30x4.htmlRead 15 October 2026CrystalDiskInfo 8.17.14 screenshot of the 1TB, firmware SN11795: Standard NVM Express 1.4, PCIe 3.0 x4
Detachable cable
Not available
Not available
Hardware
6 of 7 differ
Controller
Maxio MAP12025Reviewixbt.com/live/platform/obzor-kitayskogo-m2-nvme-nakopitelya-fanxiang-s500pro-chestnye-3500-mb-s-i-pcie30x4.htmlRead 15 October 2026iXBT Live user blog review of the 1TB, dated 2024-03-07. Its spec table, copied from the maker's store, lists Maxio MAP1202A-F1C. The teardown text reads a DRAM-less Maxio MAP1202C-F1C. The family name Maxio MAP1202 is stored. The review names no flash maker. The four flash chips are marked LGLY256G09CB112Reviewssd-tester.com/fanxiang_s500_pro_1tb.htmlRead 21 October 2026The page's table lists Maxio MAP1202 as manufacturer information, which agrees with the iXBT teardown family name
Sandisk in-house7Reviewtomshardware.com/reviews/wd-black-sn850x-ssd-review-back-in-blackRead 14 October 2026Table reads WD Proprietary. Text: updated version of the SN850 controller, still eight-channel. Maker names no controller9Reviewtomshardware.com/pc-components/ssds/wd-black-sn850x-8tb-ssd-review-the-no-compromise-8tb-championRead 14 October 2026Controller code A101-000292-B2 on the 8TB and 20-82-20035-V2 on the original. Review says SanDisk technology, an update with a higher bus rate11Reviewkitguru.net/components/ssd-drives/simon-crisp/wd-black-sn850x-with-heatsink-2tb-ssd-review/all/1Read 14 October 2026Review calls it an 8-channel Gen 4 WD controller, probably an updated version of the in-house G2 controller. Part code 20-82-20035-B213Reviewthessdreview.com/our-reviews/nvme/wd_black-sn850x-gen4-8tb-ssd-reviewRead 14 October 2026Review of the 8TB calls it a SanDisk in-house Gen 4 8-channel SSD controller
Flash type
Flash memory
Not available
Sandisk BiCS5 TLC7Reviewtomshardware.com/reviews/wd-black-sn850x-ssd-review-back-in-blackRead 14 October 2026Table reads 112-Layer BiCS5 TLC for 1TB, 2TB and 4TB. Sandisk's datasheet names only BiCS TLC9Reviewtomshardware.com/pc-components/ssds/wd-black-sn850x-8tb-ssd-review-the-no-compromise-8tb-championRead 14 October 20268TB table row reads Kioxia 162-Layer TLC (BiCS6), with 112-layer BiCS5 on 1TB to 4TB. Decoded from the flash marking. The review says BiCS6 may reach the smaller capacities later
Flash layers
Not available
DRAM cache
None, HMB not stated5Reviewixbt.com/live/platform/obzor-kitayskogo-m2-nvme-nakopitelya-fanxiang-s500pro-chestnye-3500-mb-s-i-pcie30x4.htmlRead 15 October 2026The teardown text calls the Maxio controller DRAM-less. No source says whether the drive uses host memory, so HMB not stated is stored12Reviewssd-tester.com/fanxiang_s500_pro_1tb.htmlRead 21 October 2026The same table lists DRAM cache No. It says nothing about host memory, which agrees with HMB not stated
DRAM1Maker spec sheet (PDF)documents.sandisk.com/content/dam/asset-library/en_us/assets/public/sandisk/product/internal-drives/sandisk-optimus-gx-pro/data-sheet-optimus-gx-pro-850x-internal-ssd.pdfRead 14 October 2026DRAM cache row reads Yes. The datasheet gives no size4Maker product pagesandisk.com/products/ssd/internal-ssd/sandisk-optimus-gx-pro-850x-internal-nvme-ssdRead 14 October 2026DRAM Cache: Yes
DRAM cache size
Not available
2GB7Reviewtomshardware.com/reviews/wd-black-sn850x-ssd-review-back-in-blackRead 14 October 20262TB sample: DRAM module D9XPG, a 16Gb DDR4 module from Micron with 16-bit width, 2GB of memory. Other capacities not stated11Reviewkitguru.net/components/ssd-drives/simon-crisp/wd-black-sn850x-with-heatsink-2tb-ssd-review/all/1Read 14 October 20262TB sample has a 2GB DDR4 cache chip
Component sides
Not available
Single-sided1Maker spec sheet (PDF)documents.sandisk.com/content/dam/asset-library/en_us/assets/public/sandisk/product/internal-drives/sandisk-optimus-gx-pro/data-sheet-optimus-gx-pro-850x-internal-ssd.pdfRead 14 October 2026Module code in the form factor row: S means single-sided and D means double-sided. 1TB and 2TB are 2280-S3-M, 4TB and 8TB are 2280-D5-M4Maker product pagesandisk.com/products/ssd/internal-ssd/sandisk-optimus-gx-pro-850x-internal-nvme-ssdRead 14 October 2026S3-M for 1TB and 2TB, D5-M for 4TB and 8TB7Reviewtomshardware.com/reviews/wd-black-sn850x-ssd-review-back-in-blackRead 14 October 2026Review calls the drive single-sided (2TB bare sample) and says 1Tb dies were needed to keep the 4TB single-sided. Sandisk's module code reads D5-M (double-sided) for 4TB, which is stored9Reviewtomshardware.com/pc-components/ssds/wd-black-sn850x-8tb-ssd-review-the-no-compromise-8tb-championRead 14 October 2026Review says the 8TB and the 4TB are both double-sided
Performance
4 of 4 differ
Sequential read (claimed)
3,500MB/s1Maker product pagefanxiangssd.com/products/internal-solid-state-drive-fanxiang-s500-nvme-ssd-pcleRead 15 October 2026Description reads up to 3500/3000MB/s. The 2TB row stores this page-level figure, since the maker prints no 2TB-specific table. Test conditions are not stated3Retailer pageweb.archive.org/web/20221123020954/https://www.amazon.com/dp/B0B55TQMFJRead 15 October 2026Fanxiang's brand comparison table on that listing, Performance (Read/Write): 2,800/2,000 MB/s (256GB), 3,200/2,800 MB/s (512GB) and 3,500/3,000 MB/s (1TB). The table has no 2TB column. The same listing's bullet says up to 3500/3000MB/s for the 1TB
Sequential write (claimed)
3,000MB/s1Maker product pagefanxiangssd.com/products/internal-solid-state-drive-fanxiang-s500-nvme-ssd-pcleRead 15 October 2026Description reads up to 3500/3000MB/s. The 2TB row stores this page-level figure3Retailer pageweb.archive.org/web/20221123020954/https://www.amazon.com/dp/B0B55TQMFJRead 15 October 2026Same comparison table
Random 4K read (claimed)
Not available
Random 4K write (claimed)
Not available
Endurance and reliability
3 of 3 differ
Endurance (TBW)
1,280TB1Maker product pagefanxiangssd.com/products/internal-solid-state-drive-fanxiang-s500-nvme-ssd-pcleRead 15 October 2026Description reads up to 640 TBW, which is the 1TB figure. A gallery image reads 1280 TBW next to a 3 year warranty badge and is read as the 2TB figure3Retailer pageweb.archive.org/web/20221123020954/https://www.amazon.com/dp/B0B55TQMFJRead 15 October 2026Same comparison table: 200 TBW (256GB), 320 TBW (512GB) and 640 TBW (1TB). The 2TB figure is the maker page's 1280
MTBF or MTTF (claimed)
1,500,000h7Spec databasedetail.zol.com.cn/solid_state_drive/index1428046.shtmlRead 21 October 2026ZOL (Zhongguancun Online) spec page for the S500 PRO 1TB sold in China, read in Chrome: Mean time between failures 150万小时, which is 1.5 million hours. The page names the exact model, so it is MTBF and not MTTF. It lists 3500 MB/s read and 3150 MB/s write, so it is the China-market listing. The global store and Amazon pages state no MTBF. Stored on the base only, so every capacity inherits it8Press articleithome.com/0/673/093.htmRead 21 October 2026ITHome deal article dated 13 February 2023 on the S500 Pro 2TB in China, repeating the maker's JD.com copy: 平均无故障工作时间 150 万小时, 1.5 million hours MTBF, with a 5 year warranty. ITHome articles 0/678/135 and 0/683/594 repeat the same line. The same copy claims Yangtze Memory flash and 3500/3150 MB/s, which conflict with the global pages and the iXBT teardown chip markings, so no flash maker is stored. Two sources, for the 1TB and the 2TB, give the same MTBF
Operating temperature
Power
3 of 6 differ
Power while reading (claimed)
Not available
Power while writing (claimed)
Not available
Max power consumption (claimed)
Not available
Not available
Average power in light use (claimed)
Not available
Not available
Idle power (claimed)
Not available
Not available
Measured
8 of 9 differ
Sequential read (measured)
3,591MB/s9Reviewssd-tester.com/fanxiang_s500_pro_256gb.htmlRead 21 October 2026256GB model, tested 10 January 2023. CrystalDiskMark 7.0.0 x64, 1 pass, 4 GiB test file, run on an empty drive (D: 0 percent used). The page names no port and no host. KitGuru and Tom's Hardware have not reviewed this drive, so this reviewer is used. SEQ1M Q8T1 read 3634.68 MB/s10Reviewssd-tester.com/fanxiang_s500_pro_512gb.htmlRead 21 October 2026512GB model, tested 24 January 2023. CrystalDiskMark 7.0.0 x64, 1 pass, 4 GiB test file, run on an empty drive (D: 0 percent used). The page names no port and no host. KitGuru and Tom's Hardware have not reviewed this drive, so this reviewer is used. SEQ1M Q8T1 read 3651.09 MB/s11Reviewssd-tester.com/fanxiang_s500_pro_2tb.htmlRead 21 October 20262TB model, tested 19 December 2023. CrystalDiskMark 7.0.0 x64, 1 pass, 4 GiB test file, run on an empty drive (D: 0 percent used). The page names no port and no host. KitGuru and Tom's Hardware have not reviewed this drive, so this reviewer is used. SEQ1M Q8T1 read 3591.01 MB/s
Sequential write (measured)
3,055MB/s9Reviewssd-tester.com/fanxiang_s500_pro_256gb.htmlRead 21 October 2026256GB model. Same run, SEQ1M Q8T1 write 1353.19 MB/s. It is below Fanxiang's 2000 MB/s up-to claim for this size, and the drive was empty10Reviewssd-tester.com/fanxiang_s500_pro_512gb.htmlRead 21 October 2026512GB model. Same run, SEQ1M Q8T1 write 2764.31 MB/s11Reviewssd-tester.com/fanxiang_s500_pro_2tb.htmlRead 21 October 20262TB model. Same run, SEQ1M Q8T1 write 3054.6 MB/s
Random 4K read at queue depth 1 (measured)
62.11MB/s9Reviewssd-tester.com/fanxiang_s500_pro_256gb.htmlRead 21 October 2026256GB model. Same run, RND4K Q1T1 read 65.5 MB/s, printed as MB/s10Reviewssd-tester.com/fanxiang_s500_pro_512gb.htmlRead 21 October 2026512GB model. Same run, RND4K Q1T1 read 67.92 MB/s, printed as MB/s11Reviewssd-tester.com/fanxiang_s500_pro_2tb.htmlRead 21 October 20262TB model. Same run, RND4K Q1T1 read 62.11 MB/s, printed as MB/s
Random 4K write at queue depth 1 (measured)
169.06MB/s9Reviewssd-tester.com/fanxiang_s500_pro_256gb.htmlRead 21 October 2026256GB model. Same run, RND4K Q1T1 write 170.14 MB/s, printed as MB/s10Reviewssd-tester.com/fanxiang_s500_pro_512gb.htmlRead 21 October 2026512GB model. Same run, RND4K Q1T1 write 174.75 MB/s, printed as MB/s11Reviewssd-tester.com/fanxiang_s500_pro_2tb.htmlRead 21 October 20262TB model. Same run, RND4K Q1T1 write 169.06 MB/s, printed as MB/s
Write cache size (measured)
170GB9Reviewssd-tester.com/fanxiang_s500_pro_256gb.htmlRead 21 October 2026256GB model. HD Tune Pro long-term test, 100 GB file written: the text reads that after approx. 40 GB the cache was full and performance was throttled. The table also lists the pSLC cache as approx. 40 GB.10Reviewssd-tester.com/fanxiang_s500_pro_512gb.htmlRead 21 October 2026512GB model. HD Tune Pro long-term test, 100 GB file written: the text reads that after approx. 62 GB the cache was full and performance was throttled. The table also lists the pSLC cache as approx. 62 GB. Fanxiang's Amazon table claims 3200 MB/s read for this size and this reviewer measured about 3650 MB/s, in line with the 1TB and 2TB runs, so that claim looks conservative.11Reviewssd-tester.com/fanxiang_s500_pro_2tb.htmlRead 21 October 20262TB model. HD Tune Pro long-term test, 300 GB file written: the text reads that after approx. 170 GB the cache was full and performance was throttled. The table also lists the pSLC cache as approx. 170 GB. The 2TB result is also stored on the base, since the base describes the 2TB model.
Not available
Write speed after the cache (measured)
Not available
Not available
3DMark Storage Benchmark
Not available
Highest temperature under load (measured)
Not available
85°C8Reviewtomshardware.com/reviews/wd-black-sn850x-ssd-review-back-in-black/3Read 14 October 20262TB, bare drive, tested without a heatsink or extra airflow. Writing the entire cache (15-minute Iometer sequential write) got the S.M.A.R.T. reported temperature into a throttling range between 78 and 85 C, so the top of the range is stored. Idle was 48 C. Intel Core i9-11900K, ASRock Z590 Taichi, Windows 10 Pro, drive prefilled to 50% and tested as a secondary device10Reviewtomshardware.com/pc-components/ssds/wd-black-sn850x-8tb-ssd-review-the-no-compromise-8tb-champion/2Read 14 October 20268TB, bare non-heatsink drive: maximum 68 C on the primary composite sensor, about 22 C ambient, active cooling unless noted. Intel Core i9-12900K, Asus ROG Maximus Z790 Hero, Windows 11 Pro, drive prefilled to 50%, tested as a secondary drive. Stored in the 8TB row
Idle power (measured)
Not available
1,124mW8Reviewtomshardware.com/reviews/wd-black-sn850x-ssd-review-back-in-black/3Read 14 October 20262TB, bare. Quarch HD Programmable Power Module, idle power with ASPM/LPM disabled: 1,124 mW with Game Mode off and 1,052 mW with Game Mode on. Game Mode off is stored. Value printed on the chart. The review also says the cache is almost 600 GB and the post-cache speed is below 2,000 MB/s on a chart, which are not stored as exact numbers10Reviewtomshardware.com/pc-components/ssds/wd-black-sn850x-8tb-ssd-review-the-no-compromise-8tb-champion/2Read 14 October 20268TB, Quarch idle power with ASPM/LPM disabled: 1,085 mW, printed on the chart. Stored in the 8TB row
Cooling and build
2 of 4 differ
Heatsink
Without heatsink, With heatsink1Maker spec sheet (PDF)documents.sandisk.com/content/dam/asset-library/en_us/assets/public/sandisk/product/internal-drives/sandisk-optimus-gx-pro/data-sheet-optimus-gx-pro-850x-internal-ssd.pdfRead 14 October 2026This datasheet covers the bare drives. Heatsink versions have their own datasheet2Maker spec sheet (PDF)documents.sandisk.com/content/dam/asset-library/en_us/assets/public/sandisk/product/internal-drives/sandisk-optimus-gx-pro/data-sheet-optimus-gx-pro-850x-internal-heatsink-ssd.pdfRead 14 October 2026Datasheet title reads SANDISK Optimus GX PRO 850X with Heatsink3Maker spec sheet (PDF)documents.sandisk.com/content/dam/asset-library/en_us/assets/public/sandisk/product/internal-drives/wd-black-ssd/data-sheet-wd-black-sn850x-nvme-ssd.pdfRead 14 October 2026All capacities have an optional heatsink version
RGB lighting
Not available
Yes3Maker spec sheet (PDF)documents.sandisk.com/content/dam/asset-library/en_us/assets/public/sandisk/product/internal-drives/wd-black-ssd/data-sheet-wd-black-sn850x-nvme-ssd.pdfRead 14 October 2026Dashboard text: customize your RGB lighting (heatsink versions only). The Optimus datasheets do not mention RGB7Reviewtomshardware.com/reviews/wd-black-sn850x-ssd-review-back-in-blackRead 14 October 2026Optional heatsink with RGB for the 1TB and 2TB models
Dust and water rating
Not available
Not available
Drop test height
Not available
Not available
Security and software
2 of 2 differ
Software
Not available
Compatibility
1 of 1 differ
Platforms
Windows, PS52Maker spec sheet (PDF)documents.sandisk.com/content/dam/asset-library/en_us/assets/public/sandisk/product/internal-drives/sandisk-optimus-gx-pro/data-sheet-optimus-gx-pro-850x-internal-heatsink-ssd.pdfRead 14 October 2026The heatsink text reads compatible with PS5 and PS5 Pro consoles. The PS5 line is for the heatsink models only, the bare drive is listed for Windows3Maker spec sheet (PDF)documents.sandisk.com/content/dam/asset-library/en_us/assets/public/sandisk/product/internal-drives/wd-black-ssd/data-sheet-wd-black-sn850x-nvme-ssd.pdfRead 14 October 2026System compatibility row reads Windows 10+ and PlayStation 5 (heatsink model only)4Maker product pagesandisk.com/products/ssd/internal-ssd/sandisk-optimus-gx-pro-850x-internal-nvme-ssdRead 14 October 2026Compatibility reads Windows 10+, PCIe 4.0 x4 interface and M.2 2280 port. The heatsink text reads compatible with PS5 and PS5 Pro
Dimensions and weight
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Dimensions
Not available
Length80Width22Height2.38mm(3.1 × 0.9 × 0.1 in)1Maker spec sheet (PDF)documents.sandisk.com/content/dam/asset-library/en_us/assets/public/sandisk/product/internal-drives/sandisk-optimus-gx-pro/data-sheet-optimus-gx-pro-850x-internal-ssd.pdfRead 14 October 2026Bare drive, length 80 mm and width 22 mm for all capacities. Height 2.38 mm for 1TB and 2TB, 3.88 mm for 4TB and 8TB. Footnote 8: length and width vary by +/-0.15 mm. Base is the 2TB bare drive2Maker spec sheet (PDF)documents.sandisk.com/content/dam/asset-library/en_us/assets/public/sandisk/product/internal-drives/sandisk-optimus-gx-pro/data-sheet-optimus-gx-pro-850x-internal-heatsink-ssd.pdfRead 14 October 2026Heatsink models, rounded: 80 x 23 x 8.90 mm for 1TB and 2TB, 80 x 24 x 10.31 mm for 4TB and 8TB. The WD_BLACK SN850X datasheet gives 23.40 and 24.46 mm widths, which are stored3Maker spec sheet (PDF)documents.sandisk.com/content/dam/asset-library/en_us/assets/public/sandisk/product/internal-drives/wd-black-ssd/data-sheet-wd-black-sn850x-nvme-ssd.pdfRead 14 October 2026Heatsink models: 80 +/-0.20 x 23.40 +/-0.40 x 8.90 +/-0.40 mm for 1TB and 2TB, 80 +/-0.20 x 24.46 +/-0.48 x 10.31 +/-0.50 mm for 4TB and 8TB. Bare drives 80 x 22 x 2.38 mm (1TB, 2TB) and 3.88 mm (4TB, 8TB)
Weight
Not available
7.5g(0.3 oz)1Maker spec sheet (PDF)documents.sandisk.com/content/dam/asset-library/en_us/assets/public/sandisk/product/internal-drives/sandisk-optimus-gx-pro/data-sheet-optimus-gx-pro-850x-internal-ssd.pdfRead 14 October 20267.5 g for 1TB and 2TB and 8.6 g for 4TB and 8TB. Footnote 8: weight varies by +/-1 g2Maker spec sheet (PDF)documents.sandisk.com/content/dam/asset-library/en_us/assets/public/sandisk/product/internal-drives/sandisk-optimus-gx-pro/data-sheet-optimus-gx-pro-850x-internal-heatsink-ssd.pdfRead 14 October 202624 g for 1TB and 2TB and 30.4 g for 4TB and 8TB, heatsink models3Maker spec sheet (PDF)documents.sandisk.com/content/dam/asset-library/en_us/assets/public/sandisk/product/internal-drives/wd-black-ssd/data-sheet-wd-black-sn850x-nvme-ssd.pdfRead 14 October 2026Heatsink models 24 g +/-3 g (1TB, 2TB) and 30.4 g +/-3 g (4TB, 8TB). Bare 7.5 g +/-1 g and 8.6 g +/-1 g
In the box
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In the box
M.2 SSD, Mounting screw, Screwdriver, Instruction leaflet1Maker product pagefanxiangssd.com/products/internal-solid-state-drive-fanxiang-s500-nvme-ssd-pcleRead 15 October 2026Gallery images read the package contains mounting screws and a screwdriver3Retailer pageweb.archive.org/web/20221123020954/https://www.amazon.com/dp/B0B55TQMFJRead 15 October 2026Bullet reads installation screws and screwdrivers are included in the product package. The comparison table row reads Provide installation tools4Retailer pageamazon.com/dp/B0B55TQMFJRead 15 October 2026Bullet reads the product packaging includes mounting screws and screwdrivers5Reviewixbt.com/live/platform/obzor-kitayskogo-m2-nvme-nakopitelya-fanxiang-s500pro-chestnye-3500-mb-s-i-pcie30x4.htmlRead 15 October 2026Unboxing text and photos: the drive, one screw under a seal, a screwdriver and a printed instruction leaflet
Cables included
Not available
Not available
Links
Not compared
Product page
Spec sheet
Not available
documents.sandisk.com/content/dam/asset-library/en_us/assets/public/sandisk/product/internal-drives/sandisk-optimus-gx-pro/data-sheet-optimus-gx-pro-850x-internal-ssd.pdf1Maker spec sheet (PDF)documents.sandisk.com/content/dam/asset-library/en_us/assets/public/sandisk/product/internal-drives/sandisk-optimus-gx-pro/data-sheet-optimus-gx-pro-850x-internal-ssd.pdfRead 14 October 2026Optimus datasheet, product page link named SANDISK Optimus GX PRO 850X data sheet
Manual
Not available
Not available
EPREL registration number
Not available
Not available
Warranty
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Manufacturer warranty (source market)
3years1Maker product pagefanxiangssd.com/products/internal-solid-state-drive-fanxiang-s500-nvme-ssd-pcleRead 15 October 2026Gallery image shows a 3 years warranty badge. The leaflet in the retail box says five years under Chinese quality regulations, so the maker's documents conflict. The web page badge and the Amazon listing both say 3 years4Retailer pageamazon.com/dp/B0B55TQMFJRead 15 October 2026Bullet reads a 3-year quality assurance service














