News Intel Alder Lake PCIe 5.0 Configuration Reportedly Detailed In Coreboot

[Admin]

Coreboot code allegedly exposes valuable information on Intel's 12th Generation Alder Lake-S processors.

Intel Alder Lake PCIe 5.0 Configuration Reportedly Detailed In Coreboot : Read more

 

[JayNor]

"Only AMD's Ryzen 3000 and Ryzen 5000 mainstream processors have embraced the PCIe 4.0 standard at this point."

Tiger Lake-U chips have PCIE4

 

[JayNor]

"We expect the PCIe 5.0 situation to play out the same."

PCIE5 doubles the max bandwidth per lane, so perhaps a single lane would do for a PCIE5 SSD and perhaps 3 lanes would do for a GPU.

I suspect Intel wants to use the PCIE5 to show off CXL performance increases for GPUs, since that is what they have announced with the Sapphire Rapids Server chips.

 

[JayNor]

"It would appear that neither interface supports bifurcation, meaning you can't split up the PCIe 5.0 lane or get the PCIe 4.0 lanes to operate at x8."

PCIE5 is backwards compatible with all prior pcie versions. It starts negotiations at PCIE1.

The patch comments also explicitly say that the 8 lanes of PCIE5 can be split into two groups of 4 lanes.

 

[InvalidError]

the interface is good for up to 32 GBps of bandwidth, which is more than any consumer PCIe-based device can consume.

I could imagine a low-end GPU needing to use system RAM to supplement its 4-6GB of VRAM using a good chunk of that 32GB/s. That's where the 4GB RX5500 gets its huge 4.0x8 vs 3.0x8 boost (closes 70-80% of the gaps with the 8GB variant) from. I count that as at least one thing in consumer space that could significantly benefit from it as soon as lower-end 5.0x8 GPUs become available.

 

[JOSHSKORN]

Would be great if my 6 year old PC holds out until PCI-e 5.0 appears on intel motherboards. Maybe by then, they'll have a GPU available that is actually noticeably hindered by PCI-e 3.0. From what I've seen, even with the RTX 3090, there's literally only a couple of FPS difference in performance between PCI-e 3.0 and PCI-e 4.0.

 

[InvalidError]

From what I've seen, even with the RTX 3090, there's literally only a couple of FPS difference in performance between PCI-e 3.0 and PCI-e 4.0.

With the 4GB RX5500, 4.0x8 vs 3.0x8 can make the difference between 40fps and 70fps whereas the 8GB variants score 80fps regardless, almost making the 8GB models unnecessary. Had the RX5500 had a 4.0x16 interface, the 8GB models' VRAM size advantage would have been mostly irrelevant.

People keep gawking over the high-end but it is the lower-end GPUs that would benefit the most from 5.0x16 on a DDR5 platform once the parts become affordable.

 

[InvalidError]

Surely my new Capellix AIO footprint will not cover or adequately cool the new much larger upcoming LGA 1700.

The only area of the IHS that really needs to make contact with the HSF or cooling block is the area surrounding the cores and that area is only a small fraction of the total IHS surface. As long as your AiO's manufacturer makes an updated bracket to locate the block over the correct spot, you'll be fine.

 

[JayNor]

At CES 2021, Intel gave a sneak peek at a desktop PC running Windows on an Alder Lake chip ... They also said these are coming in 2H 2021. The slide in that presentation indicated Alder Lake versions will exist for both mobile and desktop, which confirms rumors.