Showing results for 
Search instead for 
Did you mean: 

Maximus Extreme XII: PCI-E and 10th vs 11th gen.

Level 7
I'm thinking, since prices on the 11th gens are coming down, of doing a (somewhat) superfluous upgrade. Currently I have a 10900K, on the Extreme XII motherboard, along with 4 TB of PCI-E NVME on the DIMM.2 riser (2 2tb Samsung 970 Evo+s, which support PCI-E 3.0) . The problem with this is it puts the 3090 TUF OC I have into 3.0@8x, since the DIMM.2 takes up some of the PCIE lanes.

Everything I've read leads me to believe that the Extreme XII supports PCI-E 4.0, and my questions would be:

Am I correct in my information that the Extreme XII supports 11th gen @ PCI-E 4.0? I know it supports the 11th gen (and I'm on the BIOS version that does so, I updated to enable resizable BAR), but I'm not 100% on whether or not it supports PCI-E 4.0. The second question would be if I made this upgrade (the 11900k's are close to 300USD now, so it's not a terrible price) would my GPU get PCI-E 4.0@16x, and the NVME get the 3.0 speeds?

If the upgrade would still leave me at 8x on the GPU, I'd see little/no purpose (although supporting 4.0 @ 8x would still be plenty more than 3.0 @ 8x).

Yes, I know this is a monumentally superfluous upgrade, however the goal in both building the PC, and this one (last, for the foreseeable future) upgrade would be future proofing the PC to last a solid 8-10 years with minimal upgrades for a long while.

Also, it offends me everytime I see a 3090 running on 8x when I paid NewEgg Shuffle levels of money for the damn thing...


Level 14
As I understand it, the Z490 platform only supports PCIe 3.0, but ASUS designed their high end Z490 boards to PCIe 4.0 specs (double the frequency / data rate on the PCIe lanes) for the lanes that connect directly to the CPU socket. The Z490 chipset / PCH itself still only supports PCIe 3.0, so anything connected through the chipset is limited to 3.0, but anything connected directly to the CPU can probably run as 4.0 if the BIOS allows it. It sounds to me, from the ASUS tech specs page for the board, that they have hooked up the DIMM.2 slot to the 2nd x16 slot (which requires the board to be in x8 mode, running the slots as 1x8 & 2x4). Those are CPU lanes. The block diagram from the Intel® Z490 Chipset Product Brief gives you an idea of what's connected to each half of the platform:


A couple more thoughts for you. Your 3090 would be running as 4.0x8, which is the same total bandwidth as 3.0x16. There's a widely held view out there that very few GPU workloads actually need the full x16, both in past and current generations, and that running x8 doesn't hurt typical gaming performance much (or at all, in less demanding apps). 90s, Titans, other top tier cards are really the only cases where x16 might truly be needed, and that's still workload dependant. You may benefit more from running high end NVMe at 4.0 speed than you lose from running the GPU at x8. I'm running Firecuda 530s on 4.0, and those 7GB/s transfers (peak) are really quite something when dragging big files around.

Level 11
10900K & Z490 is quite a stable combination (especially if a bios before RKL is used), and 10th is better in most of the games (RDR2, Cyberpunk 2077, Watch Dogs Legion, Assassin's Creed Odyssey/Valhalla etc).
I had also Z490+11th, 10th+Z590 (this one is pretty nightmare), also 11th + Z590.
11th + 590 is so sweet for OC and especially DDR4 OC, but way below in the games mentioned above. Some games (BF5 maybe?) might have better lows though, but not the ones I was interested.

Yeah, 11th brings you PCI.E 4.0 speeds for SSD and full x16 for your video card, synthetic tests will look great on paper but in real word - ie games, zero benefits you will see.

After months of pain, I finally decided to buy back the Z490 mobo, had to throw away the Z590, as the Asus policy does not allow but national warranty (which is stupid, because I bought it online), luckily didn't sell yet my 10900K.

Z690+ 12th is a no go, see the dedicated area =))

Awesome, thanks for the replies, kind of answers my initial questions/thoughts (8x isn't a massive loss (and, won't even lie, I am certainly loving having 5TB of NVME storage on this thing) performance wise, and an upgrade would be minimal, probably unnoticeable, improvement, if even that).

And, at least for now, 3.0 vs 4.0 PCIE on NVME isn't a game changer for me-- Look, my dudes, this PC was an upgrade from a i-7 950 running a 7500 RPM 1TB HDD that I ran for nearly 10 years. It's still, two years after getting it set up, a "oh wow, damn, ****'s booted up. That's awesome" for me every time I turn the computer on 🙂