Introduction

The other day the new GIGABYTE P45-DQ6 arrived and I was instantly intrigued by how cool it looks. The thing is, what also arrived that day was the HD 4850s. With my mind going in over drive, I thought this was the perfect time to check out what's going on in the PCI Express slot department these days.

While the P45 does have some improvements over the X48, it's ultimately a replacement for the lower end P35 chipset. The X58 due out later this year will be the true replacement for the X48.

While there are a few differences between the two, we only cared about one of them. We wanted to know the performance difference between the X48 and the P45 when running Crossfire. While both boards carry two physical x16 slots, when two cards are installed the electronics behind the slots on the P45 tune back to x8 on both slots. The X48 on the other hand continues to run both slots at x16 independently.

Since we were bugging the guys down at IBuyPower Australia all weekend, we thought to ourselves "What's just one more motherboard swap?" - So, setting up our HD 4850s in the P45 and cranking the CPU up to 4GHz, we obtained some interesting results.