Choosing the Best H55/H57 Motherboard - Part 1

Testbed Setup and Power

We utilized memory kits from Corsair and G.Skill to verify memory compatibility on our test boards. Our OS and primary applications are loaded on the OCZ Vertex 120GB SSD drive and our games operate off the WD Caviar Black 1TB drive. We did a clean install of the OS and applications for each motherboard.

We used Intel's stock cooler for the stock comparison testing, while water-cooling via the superlative Heat Killer 3.0 water block was utilized for overclocking. For graphics duty, we used MSI's GTX 275 Lighting GPU to provide performance comparisons between boards during gaming benchmarks.

For our test results we set up each board as closely as possible in regards to memory timings. Otherwise all other settings are left on auto. The P55 utilized 8GB of DDR3 (apart from DFI's MI-T36 which is limited to 4GB), while the X58 platform contained 6GB. The P55 and X58 DDR3 timings were set to 7-7-7-20 1T at DDR3-1600 for the i7-920 and i7-870 processors at both stock and overclocked CPU settings.

We used DDR3-1333 6-6-6-18 1T timings for the i5-750 stock setup for all system benchmarks (non-gaming tests) as DDR3-1600 is not natively supported at a stock BCLK setting of 133.

For our Clarkdale i5 661 CPU, we used 7-7-7-20 1N timings at DDR3-1333MHz with 8GB of memory. We would have preferred to use CAS 6 timings to match our Lynnfield setup, but it seems 8GB of memory at CAS 6 on Clarkdale is not possible right now. The 4GHz gaming results used 8GB of memory at DDR3-1200 with CAS 6-6-6-18 1N timings to allow a BCLK of 200MHz with the QPI ratio in sync with CPU frequency.

There's little to separate these boards when you run them at a fixed frequency, showing nothing more than a 1-2% swing in most instances, which goes completely unnoticed in real world usage.

Power consumption

Our power consumption testing utilizes the same batch of components under similar circumstances in a bid to monitor variances between idle and CPU load conditions using an AC wall meter for power consumption measurements. We install the vendor supplied power saving utilitites on each board and enable power saving modes that don't involve any kind of underclocking or CPU core frequency modulation in order to run an apples to apples comparison.

Assuming a maximum 150w load in the worst case scenario, actual motherboard power consumption is around 15%~17% lower than the shown figures if you factor out switching losses at the PSU.

A graphics card like nVidia's 275 will add around 28w of idle power consumption to a Clarkdale system. It is unfortunate that Intel (and board vendors) do not offer drivers/GPU power management that allow a discrete GPU to be powered on/off on demand - the power savings would be rather attractive.  

Note that most of the CPU VCC power saving features on these boards need to be turned off when overclocking to ensure system stability and to prevent PWM burnouts under modulating loads at higher levels of current draw. With power saving features switched off, you get a 5~10W increase in the idle power consumption at the same operating frequency, while load power consumption remains roughly the same due to current loading.