Overclocking
Every product in today’s comparison provides wide enough frequency and timing selections to push our big air cooler to the limit, even with an ambient temperature below 22 degrees Celsius.
| BIOS Frequency and Voltage settings (for overclocking) | ||||
|---|---|---|---|---|
| ASRock P55 Deluxe | Asus P7P55D EVO | Biostar TPower I55 | EVGA P55 SLI | |
| CPU Base Clock | 100-300 MHz (1 MHz) | 80-500 MHz (1 MHz) | 100-800 MHz (1 MHz) | 133-600 MHz (1 MHz) |
| CPU Multiplier | Yes | Yes | Yes | Yes |
| DRAM Data Rates | BCLK x6 - x12 (x2) | BCLK x6 - x12 (x2) | BCLK x6 - x12 (x2) | BCLK x6 - x12 (x2) |
| PCIe Clock | 50-150 MHz (1 MHz) | 100-200 MHz (1 MHz) | 100-150 MHz (1 MHz) | 100-200 MHz (1 MHz) |
| CPU Vcore | 0.84-2.00V (6.25mV) | 1.10-1.70V (6.25mV) | +7875mV (6.25mV) | +630mV (10mV) |
| Uncore Voltage | 1.11-2.04V (14.5mV) | 1.10-1.70V (6.25mV) | 1.10-2.03V (15mV) | +630mV (10mV) |
| PCH Core | 1.07-1.49V (6.5mV) | 1.05V, 1.15V | 1.10-2.03V (15mV) | +300mV (10mV) |
| DRAM Voltage | 1.56-2.01V (14mV) | 1.20-2.50V (12.5mV) | 1.60-2.53V (15mV) | +630mV (10mV) |
| CAS Latency | 6-11 Cycles | 3-11 Cycles | 3-15 Cycles | 3-15 Cycles |
| tRCD | 3-15 Cycles | 3-15 Cycles | 3-15 Cycles | 3-15 Cycles |
| tRP | 3-15 Cycles | 3-15 Cycles | 3-15 Cycles | 3-15 Cycles |
| tRAS | 9-31 Cycles | 3-31 Cycles | 9-63 Cycles | 9-63 Cycles |
| BIOS Frequency and Voltage settings (for overclocking) | ||||
|---|---|---|---|---|
| Foxconn Inferno Katana GTI | Jetway HI05 | Gigabyte P55-UD4P | MSI P55-GD65 | |
| CPU Base Clock | 66-255 MHz (1 MHz) | 133-500 MHz (1 MHz) | 100-1200 MHz (1 MHz) | 100-600 MHz (1 MHz) |
| CPU Multiplier | Yes | Yes | Yes | Yes |
| DRAM Data Rates | BCLK x6 - x12 (x2) | BCLK x6 - x12 (x2) | BCLK x6 - x12 (x2) | BCLK x6 - x12 (x2) |
| PCIe Clock | 100-120 MHz (1 MHz) | 100-200 MHz (1 MHz) | 90-150 MHz (1 MHz) | 90-190 MHz (1 MHz) |
| CPU Vcore | -0.40-+1.26V (10mV) | -0.88-+8.00V (25mV) | 0.50-1.90V (6.25mV) | 0.87-2.70 (6.25mV) |
| Uncore Voltage | 0.95-1.50V (10mV) | 1.12-2.23V (17.5mV) | 1.05-1.99V (20mV) | 0.45-2.02V (5.38mV) |
| PCH Core | 0.95-1.50V (10mV) | 1.08-2.14V (17mV) | 0.95-2.00V (20mV) | 1.00-2.40V (10mV) |
| DRAM Voltage | 1.40-2.71V (10mV) | 1.54-3.26V (25.5mV) | 1.30-2.60V (20mV) | 0.91-2.40V (6.25mV) |
| CAS Latency | 3-15 Cycles | 3-15 Cycles | 6-15 Cycles | 4-15 Cycles |
| tRCD | 3-15 Cycles | 3-15 Cycles | 1-15 Cycles | 3-15 Cycles |
| tRP | 3-15 Cycles | 3-15 Cycles | 1-15 Cycles | 3-15 Cycles |
| tRAS | 9-63 Cycles | 9-63 Cycles | 1-31 Cycles | 9-31 Cycles |
However, not every setting is completely useful. Surely, most overclockers understand that base clock limits beyond 300 MHz are completely meaningless with the LGA 1156 platform, and not every board could fully support even our moderate 1.45V CPU core setting.
Biostar has put a lot of effort into its overclocking campaign, and that has paid off with a CPU overclocking win. Also notice the asterisk next to ASRock’s entry--this particular model wasn’t stable at 1.45V CPU core when maximum overclocks and eight Prime95 threads were applied. We found the highest practical setting for the P55 Deluxe was 1.40V, as anything higher would cause the motherboard’s over-current protection to reset the system under full load. We’re sure someone will try to prove us wrong by testing higher voltage levels with lower loads or clock speeds, but the only practical way we know to honestly increase the board’s amperage capacity is to increase VRM cooling.
Gigabyte takes a big lead over rival Asus and overclock-leader Biostar for maximum base clock, a setting that should be extremely important to multiplier-limited Core i5 owners.
Foxconn has the highest average memory overclock, while EVGA leads with two modules and Gigabyte leads when four are installed.
