Overclocking
| BIOS Frequency and Voltage settings (for overclocking) | |||
|---|---|---|---|
| Row 0 - Cell 0 | ASRock X79 Extreme4 | Asus P9X79 | Biostar TPower X79 |
| Base Clock | 90-300 MHz (1 MHz) | 80-300 MHz (0.1 MHz) | 80-300 MHz (0.1 MHz) |
| CPU Multiplier | 12x to 60x (1x) | 12x to 57x (1x) | 1x to 59x (1x) |
| DRAM Data Rates | 800-2400 (266.6 MHz) | 800-2666 (266.6 MHz) | 800-2400 (266.6 MHz) |
| CPU Vcore | 0.60-1.70 V (5 mV) | 0.80-1.70 V (5 mV) | 1.00-1.52 V (10 mV)Up to +0.54 V Offset |
| CPU VCCSA | 0.60-1.70 V (5 mV) | 0.80-1.70 V (5 mV) | 0.88-1.82 V (20 mV) |
| VTT Voltage | 0.95-1.49 V (7 mV) | 1.05-1.70 V (6.25 mV) | -0.20 to +0.50 V (10 mV) |
| X79 PCH Voltage | 0.73-1.91 V (13 mV) | 1.10-1.70 V (6.25 mV) | 1.09-1.50 V (12 mV) |
| DRAM Voltage | 1.21-1.81 V (13 mV) | 1.20-1.99 V (5 mV) | 1.15-2.08 V (12.5 mV) |
| CAS Latency | 4-15 Cycles | 3-15 Cycles | 3-15 Cycles |
| tRCD | 4-15 Cycles | 4-15 Cycles | 3-15 Cycles |
| tRP | 4-15 Cycles | 4-15 Cycles | 3-15 Cycles |
| tRAS | 9-63 Cycles | 4-40 Cycles | 9-63 Cycles |
The TPower X79's fixed and offset Vcore settings can be used simultaneously, boosting its theoretical maximum to 2.06 volts.
| BIOS Frequency and Voltage settings (for overclocking) | |||
|---|---|---|---|
| Row 0 - Cell 0 | ECS X79R-AX Black Deluxe | Intel DX79TO | MSI X79A- GD45 8D |
| Base Clock | 50-250 MHz (1 MHz) | 90-147 MHz (225 kHz) | 90-200 MHz (1 MHz) |
| CPU Multiplier | 12x to 65x (1x) | 12x to 57x (1x) | 12x to 60x (1x) |
| DRAM Data Rates | 1066-2400 (266.6 MHz) | 800-2400 (266.6 MHz) | 800-2400 (266.6 MHz) |
| CPU Vcore | -0.30 to +0.70V (10 mV) | 1.00-1.92V (5 mV) | 0.80-1.80V (5mV) |
| CPU VCCSA | -0.30 to +0.60V (10 mV) | 0.85-1.80V (5 mV) | 0.85-1.80V (5mV) |
| VTT Voltage | -0.20 to +0.50V (10 mV) | 1.05-1.80V (12.5 mV) | 0.85-1.69V (10mV) |
| X79 PCH Voltage | -0.20 to +0.30V (10 mV) | 1.10-1.50V (12.5 mV) | 0.90-1.90V (10 mV) |
| DRAM Voltage | -0.30 to +0.50V (10 mV) | 1.20-1.93V (12.5 mV) | 1.05-2.45V (15 mV) |
| CAS Latency | 3-15 Cycles | 5-16 Cycles | 5-15 Cycles |
| tRCD | 3-31 Cycles | 5-16 Cycles | 4-15 Cycles |
| tRP | 3-15 Cycles | 5-16 Cycles | 4-15 Cycles |
| tRAS | 9-63 Cycles | 15-75 Cycles | 10-40 Cycles |
Though several of this round-up’s motherboards offer base clock increments of less than 1 MHz, the best overclockers weren’t among them. ASRock’s X79 Extreme4 and MSI’s X79A-GD45 both reach 4.70 GHz. Neither could push our processor to 4747 MHz (which would have been required for 47 x 101 MHz), and the lack of more granular base clock settings results in a tie.
ECS gets excluded from this overclocking comparison because its old firmware did not support our newer C2-stepping CPU. Comparing a C1 overclock to a C2 wouldn't yield a fair result, especially since our C1-stepping chip is afflicted with a bug that prevents proper operation above a certain multiplier (and only Asus has been able to work around it). The new CPU is also less capable of supporting a 1.66x chipset-to-CPU multiplier, which puts the boards employing it at a disadvantage.
Every Sandy Bridge-E processor has a frequency window that includes an underclocking floor. ASRock’s 152 MHz base clock, which is achieved using a 1.66x strap, requires the base frequency be underclocked to 91 MHz, which is roughly the lowest setting this CPU supports.
The 1.25x strap is far easier to use, and the top three boards to employ it all reach 134 MHz. This capability is particularly useful to owners of locked processors like the Core i7-3820, since they’re still be able to increase their CPU’s frequency up to 34% beyond its highest multiplier.
Asus does wonderful things with memory overclocking, which is why we often use its products as our reference platform in memory reviews. Intel follows closely behind, though it isn’t able to effectively use its DDR3-2133 setting when all eight slots are filled. Pushing past the possible DDR3-2400 setting would require far-more-aggressive voltage adjustments than we’re comfortable using.
