iTechGuides is reader-supported. When you buy through links on our site, we may earn an affiliate commission. As an Amazon Associate I earn from qualifying purchases. Learn more
On the full-size ASUS TUF Gaming B650-PLUS and B650-PLUS WIFI, two NVMe drives should normally negotiate four lanes each when installed in M.2_1 and M.2_2 with a Ryzen 7000 or Ryzen 9000 processor. A Ryzen 8000-series desktop APU is the important exception: ASUS specifies that M.2_2 may be limited to PCIe 4.0 x2 depending on the exact processor. Verify the negotiated PCIe generation and width before treating a lower benchmark score as a hardware fault.
First identify the exact board and processor
“ASUS B650 TUF GAMING” is not a complete model name. Confirm the label on the motherboard, box, BIOS home screen or Windows System Information. The slot wiring differs between the full-size TUF Gaming B650-PLUS/ B650-PLUS WIFI, micro-ATX B650M models and B650E models. Use the manual for the exact model before applying any lane diagram.
Also record the complete Ryzen model. Ryzen 7000, Ryzen 8000G and Ryzen 9000 processors do not expose identical PCIe resources on this board.
Do these 3 things before closing this tab:
1Scan for outdated or missing drivers - takes under a minute2Clear out junk files and repair common Windows errors3Fix the driver behind crashes, sound loss and screen glitchesHow the full-size B650-PLUS slots are wired
ASUS lists three M.2 sockets on the TUF Gaming B650-PLUS WIFI (the B650-PLUS has the same core arrangement):
#1 Best Overall
- MEET THE NEXT GEN: Consider this a cheat code; Our Samsung 990 PRO Gen4 SSD helps you reach near max performance with lightning-fast speeds; Whether you’re a hardcore gamer or a tech guru, you’ll get power efficiency built for the final boss
- REACH THE NEXT LEVEL: Gen4 steps up with faster transfer speeds and high-performance bandwidth; With a more than 55% improvement in random performance compared to 980 PRO, it’s here for heavy computing and faster loading
- THE FASTEST SSD FROM THE WORLD'S FLASH MEMORY BRAND: The speed you need for any occasion; With read and write speeds up to 7450/6900 MB/s you’ll reach near max performance of PCIe 4.0 powering through for any use
- PLAY WITHOUT LIMITS: Give yourself some space with storage capacities from 1TB to 4TB; Sync all your saves and reign supreme in gaming, video editing, data analysis and more
- IT’S A POWER MOVE: Save the power for your performance; Get power efficiency all while experiencing up to 50% improved performance per watt over the 980 PRO; It makes every move more effective with less consumption
| Socket | Ryzen 7000/9000 specification | Ryzen 8000 specification | Connection and side effect |
|---|---|---|---|
| M.2_1 | PCIe 5.0 x4 | PCIe 4.0 x4 | Processor-connected |
| M.2_2 | PCIe 4.0 x4 | PCIe 4.0 x4 or x2, CPU-dependent | Processor-connected |
| M.2_3 | PCIe 4.0 x4 | PCIe 4.0 x4 | Connected through the B650 chipset; populating it suspends PCIEX16_2 |
These are ASUS specifications for the TUF Gaming B650-PLUS WIFI and TUF Gaming B650-PLUS. With Ryzen 7000 or 9000, placing two drives in M.2_1 and M.2_2 is the intended two-drive arrangement and does not automatically split them into x2 links.
What “full speed” actually means
PCIe generation
PCIe 5.0 carries more bandwidth than PCIe 4.0. M.2_1 can be Gen 5 with compatible Ryzen 7000/9000 processors; M.2_2 and M.2_3 are Gen 4 on the configurations listed above.
Rank #2
- Ideal for high speed, low power storage
- Gen 4x4 NVMe PCle performance
- Up to 6,000MB/s read, 4,000MB/s write
- Includes Acronis cloning software
- 5-year limited warranty
Link width
x4 means four PCIe lanes; x2 means two. A PCIe 4.0 x2 connection has roughly half the theoretical link bandwidth of PCIe 4.0 x4. A drive advertised as PCIe 4.0 x4 can still negotiate x2 because of the CPU, slot, firmware or a physical connection problem.
What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
Benchmark throughput
Link width is not the same as the number printed by a benchmark. Capacity, free space, temperature, queue depth, background activity and whether the SSD is the Windows system disk all change sequential and random results. Establish the link first, then investigate performance.
Rank #3
- This product has been replaced by our latest generation. Please search for the SANDISK Optimus GX 7100 NVMe SSD
- HIGH-OCTANE GAMING. Experience speeds up to 7,250MB/s read and 6,900MB/s write (1-2TB models), with up to 35% faster performance than previous generation.
- PURPOSE-BUILT. Designed for serious on-the-go gamers, with a PCIe Gen4 interface and SANDISK’s next generation TLC 3D NAND.
- MORE TIME TO CLEAR THAT CHECKPOINT. Built with laptops and handheld gaming devices in mind, with up to 100% more power efficiency over the previous generation.
- DO MORE WITH DASHBOARD. Ensure your drive is optimized for prime performance with the downloadable WD_BLACK Dashboard (Windows only).
Check the negotiated link in Windows
- Shut down and verify which physical socket contains each SSD.
- Boot Windows and open a PCIe-aware utility such as HWiNFO.
- Find each NVMe device under its storage or PCI Express information.
- Record current and maximum link speed (Gen 4 or Gen 5) and current and maximum link width (x4 or x2).
- Check once while idle and again during activity if the utility exposes both states.
A reading such as PCIe 4.0 x4 @ x4 confirms a four-lane link. PCIe 4.0 x2 @ x2 is a genuine two-lane connection. An idle display such as x4 @ x1 can be a power-saving state; recheck under load. ASUS provides current PCIe-interface guidance through its support pages.
Use CrystalDiskMark only after recording link data. A lower score alone does not prove lane sharing or a defective socket.
Rank #4
- HUGE SPEED BOOST: Get random read/write speeds that are 40%/55% faster than 980 PRO; Experience up to 1400K/1550K IOPS, while sequential read/write speeds up to 7,450/6,900 MB/s reach near the max performance of PCIe 4.0*
- BREAKTHROUGH POWER EFFICIENCY: Use less power and get more performance; Enjoy up to 50% improved performance per watt over 980 PRO, plus optimal power efficiency with max PCIe 4.0 performance**
- SMART THERMAL CONTROL: Samsung's own nickel-coated controller delivers effective thermal control; With its slim size, 990 PRO is a perfect fit for desktops and laptops that meet the PCI-SIG D8 standard***
- THE CHAMPION MAKER: Up to 65% improvement in random performance enables faster loads for an ultimate gaming experience on PS5 and DirectStorage PC games****
- SAMSUNG MAGICIAN SOFTWARE: Get the most out of your SSD with Samsung Magician's advanced yet intuitive optimization tools; Monitor drive health, protect valuable data, and receive important updates for your 990 PRO
Why a Ryzen 8000 APU can explain x2
ASUS lists different lane resources for Ryzen 8000 desktop APUs. M.2_1 is PCIe 4.0 x4, while M.2_2 is PCIe 4.0 x4 or x2 depending on the processor. A Ryzen 5 8500G, Ryzen 5 8600G, Ryzen 7 8700G or another Ryzen 8000 model can therefore make an M.2_2 drive report x2 by design. A BIOS update cannot add lanes that the processor does not provide.
If you need x4 for the second drive, put the most latency-sensitive workload in M.2_1, accept the documented x2 behavior, or consider a processor/platform with the required lane layout after checking CPU support.
Best Value
- SPEED UP PROJECTS. Launch creator applications fast with uncompromising PCIe 4.0 read speeds up to 7,100MB/s,[2] (1TB and 2TB[1] models) and write speeds up to 6,700MB/s[2] (1TB[1]-4TB[1] models).
- CREATE AND STORE MORE. Make more room for your 4K videos and high-resolution images with capacities from 500GB[1] up to 4TB[1] on M.2 2280 built with our trusted 8th generation SANDISK BiCS QLC 3D CBA NAND.
- IT GOES WHERE YOU GO. With an all-new power efficient design, your drive delivers high performance with low power, giving you more time to be productive while on the go.
- UNCOMPROMISED RELIABILITY. With up to 1,200 TBW[3] (4TB[1] model) endurance rating, your drive is designed for creators.
- KEEP YOUR DRIVE UPDATED. Monitor your SSD’s performance and check for updates with the downloadable SANDISK Dashboard application.[5]
Recommended physical arrangement
- Install the boot or fastest drive in M.2_1.
- Install the second NVMe drive in M.2_2.
- Use M.2_3 only when you need a third drive or accept its expansion-slot consequence.
On this board, populating M.2_3 suspends PCIEX16_2. ASUS does not specify that it reduces M.2_1 or M.2_2 to x2. M.2_3 can still negotiate PCIe 4.0 x4, but its traffic shares the chipset uplink with chipset-connected USB, SATA, networking and other devices. Heavy simultaneous I/O can therefore limit aggregate throughput even while the SSD reports x4.
Isolation tests that identify the fault
- Test SSD A alone in M.2_1.
- Test SSD B alone in M.2_1.
- Test SSD A alone in M.2_2.
- Test SSD B alone in M.2_2.
- Install both drives and test again.
- Write down generation and width after every change.
- If one SSD is x2 in every socket, check its specifications and firmware; it may be an electrically x2 model.
- If every SSD is x2 only in M.2_2, investigate that socket, the CPU configuration, BIOS and the AM5 socket.
- If each drive is x4 alone but one becomes x2 only when both are installed, check the exact board model, CPU lane limits and firmware behavior.
- If M.2_1 and M.2_2 remain x4 while M.2_3 or PCIEX16_2 changes, the result is consistent with the documented chipset/slot relationship.
Hardware checks before changing parts
- Reseat the SSD fully; the gold contacts should disappear into the connector and the retaining screw or ASUS Q-Latch should hold it level.
- Inspect the M.2 socket for debris and the SSD edge connector for damage.
- Check that the thermal pad and heatsink are not too thick or forcing the drive upward.
- Confirm the drive is NVMe PCIe, not SATA M.2, and note whether it is PCIe 3.0 rather than PCIe 4.0.
- Remove unnecessary expansion cards, especially anything in a slot with documented lane sharing.
- Inspect the AM5 socket for bent or poorly contacting pins if multiple PCIe devices behave abnormally.
- Monitor SSD temperature; thermal throttling lowers throughput but cannot change an x4 link into x2.
BIOS checklist
- Enter BIOS and confirm both drives are detected.
- Leave the affected M.2 or PCIe link-speed control on Auto initially.
- If Auto negotiates incorrectly, test the relevant slot manually at Gen 4, then save and reboot.
- Record existing settings before changing anything.
- Update firmware only from the support page for the exact board and revision, following the board-specific manual.
- Clear CMOS and repeat the slot-swap tests if settings remain inconsistent.
Menu names vary by firmware version. Use ASUS’s motherboard support and download center for the correct BIOS manual and update files. The board manual is available at this ASUS PDF.
When replacement is justified
Do not buy a faster SSD to cure an unverified x2 report. Replacement becomes reasonable only after a known-good drive is x2 in one specific socket, the same drive is x4 elsewhere, reseating and BIOS reset/update have not helped, and the CPU’s documented lane limits do not explain the result. A replacement board should be selected by its independent CPU-connected M.2 count, processor lane support and expansion-slot sharing—not by the B650 chipset name alone.
Recommended Free Tools
Likewise, an M.2 heatsink is useful only when monitoring shows thermal throttling. It cannot overcome a Ryzen 8000 lane restriction, and an incorrectly sized pad can create seating problems.
Quick Recap
Quick decision guide
| Observed result | Most likely interpretation |
|---|---|
| M.2_2 shows PCIe 4.0 x2 with Ryzen 8000 | Likely an expected, CPU-dependent limitation. |
| M.2_2 shows x2 with Ryzen 7000/9000 | Investigate seating, BIOS, CPU socket, SSD and motherboard. |
| Both drives show x4 but benchmarks are low | Check temperature, free space, workload, background activity and benchmark profile. |
| M.2_3 populated and PCIEX16_2 unavailable | Expected board behavior. |
| Drive absent from BIOS | Treat as detection, installation or compatibility failure, not merely a speed issue. |
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
