Sandy Bridge Memory Scaling: Choosing the Best DDR3
by Jared Bell on July 25, 2011 1:55 AM EST3DMark 11
We're going to start the graphics benchmarks with the synthetic 3DMark test. The latest version, 3DMark 11, is still very GPU dependent. However, it does include a CPU Physics test and a combined graphics/physics test for simulating those types of loads. We’ll use the overall score with the three subtests to see if we can find any areas where memory performance makes a noticeable difference.
The overall score, which is heavily based on the graphics tests, shows a mere ~1% change across the board. When you get to the graphics test, you can see that the faster memory makes absolutely no difference at all. It's not until we get to the physics test where we see some improvement from increasing the memory speed. We get performance boost of up to 11% when going from DDR3-133 to DDR3-2133. The combined test entails the rendering of a 3D scene with the GPU while performing physics tasks on the CPU. Here again, were see a very small 2% increase in performance from the slowest to the fastest.
Crysis and Metro 2033
Based on 3DMark 11, then, we’d expect most games to show very little improvement from upgrading your memory, but we ran several gaming benchmarks just to be sure. I decided to combine the analysis for Crysis: Warhead and Metro 2033 due to the virtually non-existent differences observed during these tests. Crysis: Warhead was the previous king of the hill when it came to bringing video cards to their knees. The newer kid on the block, Metro 2033, has somewhat taken over that throne. Just how do they react to the various memory configurations we're testing today?
It's worth noting that the settings used here are the settings that I would actually play these games at: 1920x1080 with most of the high quality features enabled. Frame rates are well above 30, so definitely playable, though they’re below 60 so some would say they’re not perfectly smooth. Regardless, unless you play at settings where your GPU isn’t the primary bottleneck, you should see similar scaling from memory performance.
The results weren't very stimulating, were they? Just as expected, gaming with faster memory just doesn't make any notable difference. I could have potentially lowered the resolution and settings in an attempt to produce some sort of difference, but I felt that testing these games at the settings they're most likely to be played at was far more enlightening. If you want better gaming performance, the GPU is the best component to upgrade—no news there.
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tomx78 - Tuesday, July 26, 2011 - link
Article is called "choosing the best DDR3" so I agree they should test T1. Without it whole article is useless. It still does not answer question which DDR3 is best. If DDR3-2133 can't do T1 but DDR3-1600 can which one is faster?Impulses - Monday, July 25, 2011 - link
If you're pinching pennies and trying to build a system on a budget, even the $10 premium for anything but a basic 1333 kit doesn't seem worthwhile... I actually chose my last 2x4GB kit based on price and looks more than anything, heh, the old G.skill Sniper heatspreaders (the blue-ish version) matched my MSI mobo well and looked like they'd be the least likely to interfere with any heatsink. Some of the heatspreaders on pricier kits are crazy big, not to mention kinda gaudy.Finally - Tuesday, July 26, 2011 - link
Let me repeat: You buy your RAM based on... aesthetics?No further questions, thanks.
Finraziel - Wednesday, July 27, 2011 - link
Well as this test showed, there is little performance gain to be had, so what else is there to base your choice on? Especially for people with windows it can be important. And if you buy really fast memory that wont fit under your heatsink, well, let's just say you want to insinuate someone else is dumb? :)I used to have the Corsair modules with lights on top showing activity, and while I mainly bought them for looks, they were actually useful at times to be able to quickly check if my system had totally crashed or was still doing stuff (you can sort of see the difference in the patterns in the lights).
knedle - Monday, July 25, 2011 - link
I would love to see graphs showing how much power do different ram modules consume, few weaks ago I build low power computer with Sandy Bridge and I'm still looking into how to get as much from it as possible, with as low power consumption as possible.Rajinder Gill - Monday, July 25, 2011 - link
Power savings for DRAM are generally small. As you lower the current draw (either by reducing voltage or slacker timings) you are battling in part against the efficiency curve of the VRM.On some boards the difference in power consumption between DDR3-1333 and DDR3-1866 (given voltage and timing changes) can be as little as 1 Watt.
-Raja
Vhozard - Monday, July 25, 2011 - link
"Multiple passes are generally used to ensure the highest quality video output, and the first pass tends to be more I/O bound while the second pass is typically constrained by CPU performance."This is really not true, multiple passes are used by x264 to come as close as possible to a given file size. A one-pass crf-based encode produces an equally high quality video output, given the same conditions.
Maybe you should use one-pass encodes, as they are more commonly used when file size specification is not very important.
JarredWalton - Monday, July 25, 2011 - link
Multiple passes produce higher quality by using a higher bitrate where it's needed and a lower bitrate where it's not. In a single-pass, constant bitrate encode, scenes where there's a lot of movement will show more compression artifacts. There's no need to do multiple passes for size considerations: you do a constant bitrate of 2.0Mbps (including audio) for 120 minutes and you will end up with a file size of very close to 1800MB (or if you prefer, 1717.61MiB). Variable bitrate with a single pass doesn't have an accurate file size.Vhozard - Monday, July 25, 2011 - link
Very few people still use constant bitrate encodes.x264 works with a crf (constant rate factor), which gives constant *quality*; not constant bitrate!
There is very much a need to do multiple passes for size considerations as a constant bitrate will not give them optimal quality at all.
The quality between a crf (one-pass) of 15 that reaches a filesize of lets say 1 GBwill have almost exactly the same quality as a two-pass which is set at 1 GB.
I suggest you read the x264 wiki...
JarredWalton - Monday, July 25, 2011 - link
Sorry -- missed that you said CRF and not CBF.