We've been listening to our readers and one question that seems to have popping up a lot is whether the architectural change in Lynnfield, with its integrated PCI-Express controller, will affect gaming performance significantly.
This, in theory, makes PCI-Express communication to memory and the CPU much faster by having it all on a single die, rather than having to navigate out too another separate chipset first.
That said, the QPI bandwidth between CPU and X58 chipset is massive, so does it make a difference? Comparatively the front side bus bandwidth of the older, yet immensely popular P45 chipset is far more limited; however, the DMI access to memory from PCI-Express is more direct.
If we look at multi-GPU technologies like Nvidia SLI and ATI CrossFire, Lynnfield CPUs are limited to provide a single x16 PCI-Express lane only, forcing a pair of graphics cards into two x8 slots, just like the older P45 boards, rather than full x16s from Intel's flagship X58 chipset.
Every system has plus and minus points then, so where does Lynnfield fit for gamers?
The aim of this article is not to tell you how well Lynnfield performs in games - that is saved for the CPU performance article - but how its architecture directly compares to other Intel products so we can make educated conclusions on the new CPU core itself. As such, we removed as many other performance enhancements as we could to limit the deviation from our objective, and just cut the platforms back to the barebones in order to concentrate on the difference between the different PCI-Express configurations alone.
4GB of DDR2 in dual channel at 800MHz, 4-4-4-12-1T
Asus P5Q Deluxe motherboard (2201 BIOS)
Nvidia GeForce GTX 280 1GB (Two for SLI) – operating at 602/1,296/2,200MHz using GeForce Driver Version 190.38 WHQL.
Sapphire ATI Radeon HD 4870 1GB Toxic (Two for CrossFire) – operating at 780/4,000MHz using Catalyst 9.7 WHQL
Windows Vista x64 Home Premium SP2
Seagate 7200.12 1TB Hard Disk Drive
We endeavoured to keep the CPUs to just four cores at as close to 3GHz as possible. With P45, we matched the memory clock speed to latency: where the DDR3 bandwidth is double that of DDR2, but its latencies are also all doubled accordingly. It's also worth pointing out that multi-GPU support on Intel's P45 chipset is limited to CrossFire, as SLI is not licensed.