Overclocking
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| BIOS Frequency and Voltage settings (for overclocking) | |||||
|---|---|---|---|---|---|
| Row 0 - Cell 0 | ASRock Z77 Extreme6 | Asus Z87 PRO | ECS Z87H3-A2X Extreme | Gigabyte Z87X-UD4H | MSI Z87-GD65 Gaming |
| Base Clock | 90-300 MHz (0.1 MHz) | 80-300 MHz (0.1 MHz) | 99.5-300 MHz (0.1 MHz) | 80-267 MHz (0.1 MHz) | 90-300 MHz (0.1 MHz) |
| CPU Multiplier | 8.0-120x (1x) | 8.0-80x (1x) | 16-80x (1x) | 8-80x (1x) | 8-80x (1x) |
| DRAM Data Rates | 800-4000 (200/266.6 MHz) | 800-3200 (200/266.6 MHz) | 800-3000 (200/266.6 MHz) | 800-2933 (200/266.6 MHz) | 800-3200 (200/266.6 MHz) |
| CPU Vcore | 0.80-2.00 V (1 mV) | 0.001-1.92 V (1 mV) | 0.00-2.00 V (1 mV) | 0.50-1.80 V (1 mV) | 0.80-2.10 V (5 mV) |
| VCCIN | 1.20-2.23 V (10 mV) | 0.80-3.04 V (10 mV) | -1 to +1 (Offset Only) | 1.00-2.91 V (10 mV) | 1.80-3.04 V (10 mV) |
| PCH Voltage | 0.97-1.32 V (5 mV) | 0.70-1.50 V (12.5 mV) | 1.06-1.68 V (10 mV) | 0.65-1.30 V (5 mV) | 1.05-1.68V (10 mV) |
| DRAM Voltage | 1.17-1.80 V (5 mV) | 1.20-1.92 V (5 mV) | 1.10-1.82 V (5 mV) | 1.15-2.10 V (5 mV) | 0.30-2.45 V (25 mV) |
| CAS Latency | 4-15 Cycles | 1-31 Cycles | 4-18 Cycles | 5-15 Cycles | 5-15 Cycles |
| tRCD | 3-20 Cycles | 1-31 Cycles | 4-18 Cycles | 4-15 Cycles | 5-15 Cycles |
| tRP | 4-15 Cycles | 1-31 Cycles | 4-18 Cycles | 4-15 Cycles | 5-15 Cycles |
| tRAS | 9-63 Cycles | 1-63 Cycles | 10-40 Cycles | 5-63 Cycles | 10-40 Cycles |
Most of the firmware ranges presented by today’s motherboards are extremely unrealistic, as LGA 1150-based processors are generally limited to around 10% base clock alteration (beyond base clock ratio changes) and a maximum DRAM data rate of 22x 133 MHz (2,933 MT/s). Higher memory multipliers aren’t supported by Haswell CPUs, but combining a functional multiplier with a higher base clock is still an option.
Gigabyte ties Asus for the highest CPU clock, with MSI trailing only slightly behind. ECS reaches 4.5 GHz, but I wasn’t able to prevent it from using the standard two-ratio drop to 4.3 GHz when loading four cores.
Asus and Gigabyte also have the highest base clock, though Intel told our editor-in-chief, Chris Angelini, that ratio selection isn’t available for multiplier-locked Haswells. Other boards had trouble using the 166 MHz ratio, though we don't see any practical reason to do so with our air-cooled Core i7-4770K.
ECS bragged to me that it had the best-overclocking motherboard, and when I told the company otherwise, it referred to memory data rate. Indeed, the Z87H3-A2X ties Asus’ Z87-Pro for top memory clock.
