Tuesday, July 5th 2022
Intel Raptor Lake-S CPU-attached NVMe Storage Remains on PCIe Gen4
Intel is preparing to launch its next-generation desktop platform codenamed Rocket Lake-S. According to the presentation held by Intel today in Shenzen, China, we have official information regarding some of the platform features that Raptor Lake is bringing. Starting with memory support, Raptor Lake is still carrying the transitional DDR4 and DDR5 support, as the full swing towards DDR5 is still in progress. Unlike the previous generation Alder Lake, which brought DDR5-4800 support, Raptor Lake's integrated memory controller can drive DDR5 modules with a 5600 MT/s configuration. As DDR4 support remains, it is limited to 3200 MT/s speed.
Interesting information from the leaked slide points out that support for CPU-attached NVMe storage remains PCIe Gen4. While AMD will provide an AM5 socket with CPU-attached NMVe storage on PCIe Gen5 protocol, Intel is taking a step back and holding on to Gen4. The CPU is outputting 16 PCIe Gen5 lanes on its own. Motherboard vendors for the upcoming 700-series boards for Raptor Lake can still provide a PCIe Gen5 NVMe slot; however, it will have to subtract eight Gen5 lanes from the PCI Express Graphics (PEG) slot and route them to NVMe storage. As our testing shows, this will affect GPU's performance by a few percent. AMD's upcoming AM5 platform has no such issues, as the CPU provides both the PEG and CPU-attached NVMe storage with sufficient PCIe Gen5 bandwidth.
Source:
Baidu
Interesting information from the leaked slide points out that support for CPU-attached NVMe storage remains PCIe Gen4. While AMD will provide an AM5 socket with CPU-attached NMVe storage on PCIe Gen5 protocol, Intel is taking a step back and holding on to Gen4. The CPU is outputting 16 PCIe Gen5 lanes on its own. Motherboard vendors for the upcoming 700-series boards for Raptor Lake can still provide a PCIe Gen5 NVMe slot; however, it will have to subtract eight Gen5 lanes from the PCI Express Graphics (PEG) slot and route them to NVMe storage. As our testing shows, this will affect GPU's performance by a few percent. AMD's upcoming AM5 platform has no such issues, as the CPU provides both the PEG and CPU-attached NVMe storage with sufficient PCIe Gen5 bandwidth.
44 Comments on Intel Raptor Lake-S CPU-attached NVMe Storage Remains on PCIe Gen4
I welcome rapid lake & AM5, along with RX 7000 & Nvidia's 4000 series coming out before year end... what a time to be alive! :peace:
As for other use cases that aren't DirectStorage, what real-world SSD scenario requires 13.5GB/s transfers in a way that will provide meaningful improvements that a human being can notice compared to what they'll get with "only" 7GB/s transfers of PCIe 4.0 x4? The only benefit I can think of right now is being able to stroke fragile egos when they see a 5-digit number in CrystalDiskmark instead of a 4-digit number ;)
I guess if the GPU can do away with only using 8 lanes, the remaining 8 can be split for the NvMe why not. Can it also do 12+4 or is it strictly 8+8.
8 lanes for GPU, 8 lanes for SSD is ideal, and that frees up the 4 additional lanes that the SSD would otherwise be using if the GPU had all 16.
Another x4 for NVMe drive from CPU is availabel too, plus everything what is on chipset. Plenty of devices can run.
Hope TPU isnt trying to overplay newer pcie gen importance.
For those who really want the epeen of a gen5 nvme, just buy a pcie adaptor and install the gen 5 drive in there, likely sub 1% affect on the GPU.
gen5 in general is a waste on consumer hardware.
On the other hand, the AMD strategy of going for gen5 nvme first was smarter because storage is already able to saturate gen4 ports (even if there aren't pratical advantages to do so) and they went after the storage manufacturers so gen5 SSDs actually exist any time soon to take advantage of the 5.0 m.2 slots.
Intel are playing chicken-and-egg with PCIe 5.0. There's nothing to really put in a PCIe 5.0 slot, but nobody else will make a consumer PCIe 5.0 device unless the slot is already released to the consumer market.
Thanks, once again, to all the paying beta testers who spent big money on a platform that will be obsolete before things that can meaningfully take advantage of that platform arrive. We'll all be rocking i5-14600 24-core processors on B860 motherboards by the time software that can take advantage of a PCIe 5.0 SSD is common enough to be worth worrying about....