Our Search For The Ultimate DRAM
In the past several years, enthusiasts have seen storage capacity (and performance) explode. Graphics cards are immensely faster. And CPUs operate more efficiently.
System memory doesn't evolve as quickly, though. Just look back to the math I did in Haswell And Richland Memory Scaling: Picking A 16 GB DDR3 Kit. We've been stuck with approximately 8.5 ns turnaround time for more than ten years. Really, single-DIMM capacity is the one variable that keeps getting nudged up.
Today, enthusiasts are pushing 8 GB modules closer to the mainstream. This capacity isn't new. However, technical issues kept it out of the fastest builds up until recently. Increased density often imparts a latency penalty, and those modules had to hit a sub-9 ns sweet spot before the power users out there would call them performance parts. Intel pushed progress along a little with a more robust memory controller in its Haswell-based CPUs, and ratings like DDR3-1600 CAS 7 (8.75 ns), DDR3-1866 CAS 8 (8.57 ns), and DDR3-2133 CAS 9 (8.44 ns) became the benchmark for 16 GB dual-channel kits.
I covered the 16 GB market in that previously-linked round-up. However, the battle between capacity and performance continues for anyone who wants more. As with increased density, adding modules also has a negative effect on overclocking capability.
Recently, I noticed a spate of press releases in my inbox extolling four-DIMM DDR3-3000 kits that never actually showed up for purchase. A majority went to sponsored overclockers, I figured. But they got me thinking: just how far will a quartet of today's top modules go when we load down a Haswell-based system with 32 GB?
| Rated Specifications | ||||
|---|---|---|---|---|
| Row 0 - Cell 0 | Data Rate | Timings | Voltage | Warranty |
| 2 x Adata XPG DDR3 AX3U2800W8G12-DGV | DDR3-2800 (XMP) | 12-14-14-36 | 1.65 Volts | Lifetime |
| Corsair Vengeance Pro CMY32GX3M4A2800C12R | DDR3-2800 (XMP) | 12-14-14-36 | 1.65 Volts | Lifetime |
| G.Skill Ripjaws X F3-2400C11Q-32GXM | DDR3-2400 (XMP) | 11-13-13-31 | 1.65 Volts | Lifetime |
| Kingston HyperX Beast KHX24C11T3K4/32X | DDR3-2400 (XMP) | 11-13-13-31 | 1.65 Volts | Lifetime |
| Patriot Viper 3 PV332G240C1QK | DDR3-2400 (XMP) | 11-13-13-31 | 1.65 Volts | Lifetime |
We only invited companies that could provide us with four-DIMM, 32 GB sets. Adata ended up sending in two of its 16 GB dual-module kits, which we concluded was fair enough, since enthusiasts are certainly within their right to double up on a configuration like that to hit 32 GB. But the company could run into trouble if its modules are programmed to operate with one module per channel. Often, two DIMMs per channel require relaxed latency settings.
So today, Adata competes against the similarly-rated Corsair kit, which is programmed with the looser secondary timings often needed for two modules per channel at high data rates.
Other contenders enter the fray with DDR3-2400-rated sets priced more conservatively. But really, our primary goal is to identify the paramount module set. Any attractive values we find along the way are purely incidental. This story is all about being the best.
