Sandy Bridge Memory Scaling: Choosing the Best DDR3
by Jared Bell on July 25, 2011 1:55 AM ESTLINPACK Benchmark
At first I wasn't going to include the results of the LINPACK benchmark, but I figured there's no reason for them to go to waste as they were used for stability testing. The LINPACK benchmark is a measurement of a system's floating-point computing power. Today, it's widely used by enthusiasts for testing the stability of their overclocked systems. The later versions of LINPACK include support for Intel's AVX instruction set, which stress the CPU and RAM even more than before. We'll be using a front end to the LINPACK benchmark called LinX.
Now we begin to see how that extra ~36% of bandwidth really affects system performance. As you can see, there's not exactly a ~36% advantage in LINPACK from the fastest to the slowest. Here, we're barely seeing a ~3% advantage for the faster memory. Once we get to DDR3-1600, there's not much of a difference at all.
PCMark 7
We'll measure overall system performance using the PCMark suite. This will perform a broad range of tests including video playback, video transcoding (downscaling), system storage (gaming), graphics (DX9), image manipulation, system storage (importing pictures), web browsing, data decrypting, and system storage (Windows Defender).
If you take a step back and look at performance from an overall perspective, you can see that faster memory doesn't really have much of an effect. Every speed tested shows a ~2% performance increase over the slowest memory. Outside of CAS 9 DDR3-1333, then, you can pretty much use any DDR3 memory and get close to optimal performance in general applications.
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Rick83 - Monday, July 25, 2011 - link
Fancy heat spreaders are the worst that has ever happened to RAM.It gets worse when you have to pay more to get rid of it, as with the new low profile vengeance series from corsair.
Memory doesn't usually get that hot anyway, and the large heat spreaders impede airflow between the modules in fully populated setups, as well as limit what size your cooler can be, occasionally forcing you to get one of those water-cooler-in-a-box things which incur massive extra costs.
The only reason I don't want to have completely naked memory, is that the heat spreader gives the RAM some ESD protection, which is actually useful.
JoJoman88 - Monday, July 25, 2011 - link
The review just made your post the truest of them all jabber!Spacecomber - Monday, July 25, 2011 - link
In the past, one reason to get faster rated memory is that you eventually would see a migration of what was the standard memory module to something running on a faster bus speed. I'm not sure if that really holds true, anymore. It seems that these days you are more likely to see the adoption of a completely new type of memory, rather than an existing standard sticking around long enough for the minimum required memory speeds it is based on to go up.geofelt - Monday, July 25, 2011 - link
One of the price differentiators is the heat spreaders.Apart from the aesthetics, where is the value of fancy heat spreaders? Can it be measured?
Seems to me that they are mostly marketing gimmicks, excepting perhaps for those used on overclocking competitions.
I would like to see some sort of a study to determine the value of heat spreaders.
MrSpadge - Wednesday, July 27, 2011 - link
Short answer: nothing.MrS
BobDavid - Monday, July 25, 2011 - link
see subjectJarredWalton - Monday, July 25, 2011 - link
See the conclusion; we already did a look at that (with HD 3000 and Llano).http://www.anandtech.com/show/4476/amd-a83850-revi...
LoneWolf15 - Monday, July 25, 2011 - link
Ivy Bridge will be out next year. There is a reasonable chance it could have a bump in memory bandwidth. Buy RAM at one or two multipliers above what you need now, and when the upgrade comes along, you won't be wishing for new RAM.DDR3 is so cheap right now, it's worth planning ahead.
dman - Monday, July 25, 2011 - link
I've been looking for a review like this for a while, was a good read even if it didn't come as a huge surprise. I'm definitely interested in the AMD platform results if/when those are available.SteveSweetz - Monday, July 25, 2011 - link
I was disappointed to see this article lacked the detail (and quantity) of the gaming tests versus it's predecessor on AnandTech: http://www.anandtech.com/show/2792/10That article showed that memory frequency and latency changes had a greater impact in some games than others, and that in most cases the memory also had a greater impact on the minimum framerate (an important consideration) than average framerate.
Also disappointing to see no CAS6 sticks tested here. Particularly because 2GB 1600MHz CAS6 were relatively common at one point, but now, for whatever reason, G.Skill is the only company that still makes them. It'd be interesting to see if that's a meaningful exclusive. The previous article showed CAS latency being more important than frequency in some cases.