Tom's Hardware compared 3 Intel Z68 Express chipset motherboards - ASRock Z68 Extreme4, Asus P8Z68-V Pro, and Gigabyte Z68X-UD3H-B3. These are compatible with 32nm Sandy Bridge LGA 1155 socket processors, which are the Core i7, Core i5, Core i3, and some Pentium G-series models.
'The P8Z68-V Pro has the best overall performance, but the difference between it and the Z68 Extreme4 is less than 1%. The average difference is too small to show up on the chart, and ASRock had better efficiency.' [tomshardware]
'The real reason why we can’t hand the win to the P8Z68-V Pro is its compromised expansion card slots. Using the bottom slot at x4 results in two x1 slots and two onboard controllers being disabled. In other words, the bottom graphics card slot turns out to be more gimmick than feature, and may cause system builders to feel like they’ve been duped.' [tomshardware]
'ASRock adds a PCIe bridge to its Z68 Extreme4. Anyone who really wants a x4 slot should view this as mandatory. So, ASRock wins our Recommended Buy award.' [tomshardware]
So, the motherboard to get is the ASRock Z68 Extreme4, for a proper x4 slot. Remember, the mobo chipset and spec is crucial for system performance, and should never be taken lightly.
More details at Tom's Hardware - Z68 Express Roundup
