Question Z690 to Z790 (Extreme)

[Light Hope]

Hello everyone,

I’m seeking advice on whether upgrading my motherboard will significantly improve the performance of the multiple storage drives in my system. My current setup is as follows:

• CPU: Intel Core i9-13900KS
• GPU: NVIDIA GeForce RTX 4090 (MSI SUPRIM X Liquid 24G)
• Motherboard: ASUS ROG Maximus Z690 Hero
• RAM: 128GB Corsair Dominator Platinum
• Storage:
  • OS Drive: 250GB Samsung 980 Pro NVMe SSD
  • Gaming Drive: 2TB Samsung 980 Pro NVMe SSD
  • Additional Storage:
    • 2 x 8TB Corsair MP600 PRO XT M.2 NVMe PCIe Gen4 x4 SSDs
    • 1 x 8TB addlink S95 Gaming PCIe Gen4 M.2 NVMe 3D TLC NAND SSD (Up to 7000 MB/s)
    • 6 x Samsung 870 QVO SATA SSDs (4 configured in RAID 0)

When transferring files between drives, I’ve noticed inconsistent speeds. Transfers may start at 2–3 GB/s but drop to a few hundred MB/s and often stabilize around 100 MB/s. Occasionally, the rate drops to zero for a few seconds before resuming. These results seem far below the capabilities of my storage devices, leading me to believe there may be a bandwidth limitation with my current motherboard.

An ASUS Technical Support Advisor suggested upgrading to the ASUS ROG Maximus Z790 Extreme, claiming it would improve storage performance for the following reasons:

1. Increased PCIe Lanes​

• The Z790 chipset offers more PCIe lanes than the Z690, providing additional bandwidth for high-speed devices.
• With the Z690, the limited lanes can become oversaturated when connecting multiple NVMe drives, GPUs, or other devices, throttling overall performance.
• The Z790's additional lanes ensure each device can communicate with the CPU and chipset without bandwidth contention, potentially reducing throttling during simultaneous read/write operations.

2. Improved Bandwidth Allocation​

• The Z790’s architecture provides better prioritization and allocation of PCIe lanes to M.2 slots, enabling high-speed NVMe drives to operate closer to their peak potential.
• On the Z690, the chipset often reroutes bandwidth to accommodate multiple devices, which can dynamically throttle individual drive performance.
• The Z790 minimizes this dynamic throttling, especially when using multiple Gen4 drives like the Corsair MP600 PRO XT and addlink S95, leading to more consistent and faster transfer speeds.

3. Enhanced Performance Features​

• While my Gen3 and Gen4 drives cannot utilize PCIe 5.0, the Z790’s optimized storage firmware and reduced latency can still improve real-world performance.
• Its better cooling design helps prevent thermal throttling during sustained transfers, especially with high-capacity drives like my Corsair and addlink M.2 SSDs.
• RAID management on the Z790 may also perform more efficiently, reducing overhead and increasing throughput.

Potential Disadvantage of the Z790 Extreme:​

• A significant amount of data traffic on the Z790 motherboard flows through the chipset rather than directly to the CPU. This design could still result in bottlenecks during heavy usage scenarios, particularly when using multiple NVMe drives in conjunction with other bandwidth-heavy components.
• Unlike CPU-attached lanes, chipset bandwidth is shared among devices, meaning adding more drives or peripherals could impact transfer speeds despite the additional PCIe lanes.

Questions for the Community:​

1. Are the technical explanations provided by ASUS accurate, and would the Z790 genuinely lead to significant improvements in real-world storage performance?
2. Could my issues (e.g., inconsistent transfer rates, bottlenecks) be primarily due to the number of drives connected to the Z690, rather than the chipset itself?
3. Are there better ways to optimize my current configuration (e.g., RAID adjustments or drive layout) that would resolve these issues without requiring an upgrade?

I want to be very clear: some people may have concerns about the number of drives I have or why I’ve configured several in RAID 0. I’m not here looking for suggestions or criticism in that regard. I’m simply looking for advice and guidance on whether upgrading my motherboard is the right move for improving drive performance.

Thank you in advance for your help!

 

[thestryker]

You likely are running into bandwidth limitations and going from Z690 to Z790 isn't going to alleviate anything. The chipsets both have the same DMI and number of PCIe lanes with the only difference being allocation of PCIe 3.0 vs 4.0 but this doesn't change total bandwidth. You're simply not going to get peak performance on a desktop platform using that kind of storage setup.

I do think it would be worthwhile to see if you can figure out where the issue lies specifically though. You should have no problem copying between any single pair of drives (meaning RAID to NVMe, NVMe to NVMe, NVMe to SATA etc). Once you start using multiple links though you will have issues because the chipset is connected through a DMI link that maxes out at PCIe 4.0 x8.

It would probably be a good idea to have the SSD which sees most usage on the CPU lanes even if it's not your boot drive just to keep it off the chipset.

I'm not sure if you're using the PCIe 5.0 M.2 slot on your motherboard, but if you aren't that would potentially be an option though it would drop your primary slot to 8 lanes which would have a minor impact on video card performance.

 

[Light Hope]

You likely are running into bandwidth limitations and going from Z690 to Z790 isn't going to alleviate anything. The chipsets both have the same DMI and number of PCIe lanes with the only difference being allocation of PCIe 3.0 vs 4.0 but this doesn't change total bandwidth. You're simply not going to get peak performance on a desktop platform using that kind of storage setup.

I do think it would be worthwhile to see if you can figure out where the issue lies specifically though. You should have no problem copying between any single pair of drives (meaning RAID to NVMe, NVMe to NVMe, NVMe to SATA etc). Once you start using multiple links though you will have issues because the chipset is connected through a DMI link that maxes out at PCIe 4.0 x8.

It would probably be a good idea to have the SSD which sees most usage on the CPU lanes even if it's not your boot drive just to keep it off the chipset.

I'm not sure if you're using the PCIe 5.0 M.2 slot on your motherboard, but if you aren't that would potentially be an option though it would drop your primary slot to 8 lanes which would have a minor impact on video card performance.

Hi,

Thank you for your insight.

What if I upgraded to the ROG MAXIMUS Z890 EXTREME Motherboard.

Would that make a difference?

 

[thestryker]

ARL has 4 lanes of PCIe 4.0 for M.2 and 4 lanes of PCIe 5.0 for M.2 from the CPU, but that's the only difference storage wise between the two platforms (it also has built in TB 4.0, but that's a very expensive proposition). This would require a new CPU on top of the new motherboard so I don't really think that'd be a worthwhile investment.

 

[Light Hope]

I forgot to mention, that 3 out of the M.2 drives are installed on the motherboard and the other 2 are installed on a Hyper card.

 

[thestryker]

That shouldn't make any difference really, but it would be another thing to test.

Here's just some generic ideas for verifying performance:

• First of all make sure there's at least 10-20% free space on each of the drives
• Make sure you know which drive is connected where with regards to the NVMe ones
• Run CrystalDiskMark on each of the drives individually (and the RAID array) just to make sure none of the drives are misbehaving by themselves
• Get together ~50GB worth of data you can copy around between the drives (nothing individually under 2-3GB) and then copy it between drives one at a time (and the RAID array)