Discussion Don't believe all the hype about PCIe 5.0 - - - motherboards are not ready!

[thestryker]

Can you elaborate? Can I have a link to anything regarding this: x16 vs x8 usages (speeds)?

The PCIe slot runs half bandwidth, but that doesn't mean anything for most video cards. You should read the introduction and conclusion to the TPU article linked above as well as even though it's their old test platform it's still applicable. Hardware Unboxed did some PCIe testing and the most dramatic results they saw were when the video card was running out of memory so it was copying over the PCIe bus more. This is a situation which should not be happening and performance will still be very poor, but more bandwidth made it less bad.

PCIe 5.0 x8 = PCIe 4.0 x16, which isn't even close to a bottleneck yet. Heck, I saw a recent test that showed even PCIe 3.0 x16 isn't that much of a bottleneck, loosing only a handful of FPS.

PCIe is backwards compatible, but it's dependent on two things: slot revision and the revision of the card being put into it. If you put a PCIe 4.0 card into a 5.0 slot the slot runs 4.0 to match the card. If you put a PCIe 4.0 card into a 3.0 slot the card runs 3.0 to match the slot.

Thank You, and true. I should have read deeper into the manual before purchase. We are focused on the PCIe 5.0 SSD blazing speeds, not noticing the limits of the chipset to run them.

Due to the limited lanes on consumer platforms in general you have to be pretty vigilant about making sure what you're getting. For example the newest ~$250-400 MSI Z790 boards only have PCIe 5.0 M.2 from the CPU so if you want to use all the M.2 slots you have to halve the PCIe slot bandwidth. It took me a long time to find a board which suited my needs for replacing my old server with 12th Gen Intel.

 

[foscooter]

Thanks all for your comments, mostly were kind!

After reviewing many of the comments, and investigating the information given, I have put the PCIe5.0 SSD BACK into the system and running the PCIe 5.0 slot with the graphics card in it at only 8x speed.

All seems well. The drive in insanely fast and is total overkill (Crucial T705 2TB)! I left all the "temp" files alone and only installed a 1GB RAMDisk for internet cache (Temporary Internet Files, edit thru system settings and/or REGEDIT).

I find it hard to believe that in this day and age, graphics cards STILL can't saturate the PCIe 4.0 bandwidth, but SSDs are getting ever closer (even if it's x16 vs x4).

Thanks again, and I'll close this thread.

Hello moderator: please close!