The testing setup, plus overclocking
Comparison Memory |
|||
|---|---|---|---|
Patriot Viper 3 8GB |
G.Skill TridentX 8GB |
Corsair Vengeance 8GB |
|
| Model | PV38G213C1K |
F3-2400C10-8GTX |
CMZ8GX3M2A1600C9 |
| Capacity | 8GB (2x4GB) |
8GB (2x4GB) |
8GB (2x4GB) |
| Speed | 2,133MHz DDR3 |
2,400MHz DDR3 |
1,600MHz DDR3 |
| Timings | 11-11-11-27-2T |
10-12-12-31-2T |
9-9-9-24-2T |
| Voltage | 1.50V |
1.65V |
1.50V |
| Price* | £48 |
£85 |
£40 |
| Cost per GB* | £6 |
£10.62 |
£5 |
| *Approximate, correct at time of writing | |||
Test bench |
|||||||||
|---|---|---|---|---|---|---|---|---|---|
| CPU | Intel Core-i7 3770K Ivy Bridge | ||||||||
| Motherboard | Gigabyte Z77-D3H | ||||||||
| Storage device | Corsair V128 SSD | ||||||||
| Graphics card | Intel integrated HD 4000 Graphics | ||||||||
| Power supply | Corsair AX750 | ||||||||
| Operating system | Windows 7 Ultimate SP1, 64-bit | ||||||||
Benchmarks |
|---|
| SiSoft SANDRA (download) |
| HEXUS.PiFast (download) |
| PCMark 7 (download) | 3DMark 11 v1.0.3.0 (homepage) |
| 3DMark Vantage v1.2.0 (homepage) |
| Just Cause 2 (homepage) |
| Batman: Arkham City (homepage) |
Notes
How best to test memory on an Ivy Bridge platform? Rather than show you minute differences by comparing kits that are very nearly the same in specification we're taking a different tack here. We've benchmarked the Viper 3 pack on our Ivy Bridge test platform and compared it against a DDR3-1,600 pack of the same capacity run at 9-9-9-24-2T timings, representing a generic set, along with G.Skill's 2,400MHz-rated TridentX pack.
You'll notice that we're testing with a tRAS (Row Access Time) of 27 cycles, as reported by CPU-Z, rather than the 30 quoted on the modules, though it was showing as 30 cycles in the BIOS. The reason for this rests with how our test Gigabyte board implements the XMP timings. We left it at XMP for the ensuing testing.
The Core i7-3770K has four cores and eight-thread processing ability. Applications that stress these cores/threads may need access to memory outside of the chip's cache and this is where super-fast system RAM comes in. Further, as the Ivy Bridge chips feature integrated graphics that are a step above those present on Sandy Bridge models, and the IGP draws its bandwidth allocation from system memory, chances are that fast system RAM can make a meaningful contribution when gaming on the IGP.
On paper, then, medium-latency 2,133MHz memory is plainly more desirable than 1,600MHz RAM, but the excellent efficiency of the Ivy Bridge CPUs' on-chip cache may reduce the expected performance gap to practically zero.
Overclocking
The test Gigabyte board offers a wide range of memory ratios that enable the user to run the memory at various frequencies without having to adjust the base clock. The Patriot Viper 3's is, naturally, 21.33x, though the board provides 24x (2,400MHz), 26x (2,600MHz), 26.66x (2,666MHz, etc.), 28x, 29.33x, 30x, and 32x. In short, you'll likely run out of frequency headroom than encounter board-related restrictions.
Increasing the voltage to 1.65V, keeping the latencies the same and trying to run 24x (2,400MHz) resulted in a failed boot, hinting that these modules can't scale much past the rated frequency. Increasing the timings to a more-relaxed 11-13-13-35-2T caused clear instability at 2,400MHz. Reducing the timings down to a standard 9-9-9-24-2T enabled us to achieve a solid 1,866MHz. Based on our sample of one, you won't be able to eke out a great deal of additional performance.
