Performance impact of DDR3 speed of 2400, 3000MHz and more

[Sheep221]

I've seen several ads on the top of the forums header where G-skill advertises RAM sticks with 2400 to 3000 MHz clocks, but does it has any impact on performance, if any at all? I think that the CPU-bound/on-die memory controllers very much made the RAM speed parameter an invalid number for real performance.
Is it marketing trick of promoting big numbers or it really is used in some applications? If yes what is the difference when using regular 1333/1600 RAM.

 

[Cerb]

http://www.legitreviews.com/article/1779/4/

http://www.anandtech.com/show/4503/sandy-bridge-memory-scaling-choosing-the-best-ddr3/7

http://www.anandtech.com/show/6372/...-to-ddr32400-on-ivy-bridge-igp-with-gskill/12
(note: IGP testing w/ SPECviewperf)

http://www.tomshardware.com/reviews/phenom-ii-ddr3,2319-7.html

http://www.hardwarecanucks.com/foru...amd-bulldozer-fx-8150-processor-review-5.html

The difference is small, even when it does have more of an impact that choosing different motherboards would. Also note that 1 clock changes in timings give almost as much as improving the speed by 133MHz does, on average, sometimes more-so (see L4D in the TH article, FI), or Crysis in AT's SB article).

 

[Sheep221]

Just checked the benches, yes there is little to no difference. Why they then make them with such a high freqency if it does nothing?

 

[A5]

Because people will pay for it.

 

[Topweasel]

In real world testing the only conceivable way to really to get a real performance benefit out of speeding up the ram is if you were running an ondie GPU. But first you would actually want to use that.

 

[Cerb]

Just checked the benches, yes there is little to no difference. Why they then make them with such a high freqency if it does nothing?

$$$. It could be nice just IGP--those numbers work out very well for both Intel and AMD--as long as you don't spend too much more than 1333/1600 costs.

 

[Sheep221]

Yes it is effective for IGPs in technical principle, but unless IGPs replace conventional dedicated graphics cards it is pointless too.

Not sure if many enthusiasts buy these sticks when they don't increase performance.

 

[Cerb]

Yes it is effective for IGPs in technical principle, but unless IGPs replace conventional dedicated graphics cards it is pointless too.

If you got an AMD APU, FI, you would do well to spend $10-20 more for 1866 or 2133MHz RAM, as long as the timings were OK, compared to spending $50+ on a card. For most people IGP has replace cards. If Haswell's drivers are alright, it'll even be true for Intel's (well, it already is, but people still bitch after they saved money on their IGP-only laptop ).

Not sure if many enthusiasts buy these sticks when they don't increase performance.

Faster is better for marketing, I think. Kind of like the little closed loop water coolers that don't perform any better than a good heatpipe air cooler.

 

[Sheep221]

That's true that if owning an APU it is good to have it.

But even when the IGPs will be enough strong, I assume the dedicated video RAM is still way faster, GDDR5 at 1500MHz will transfer upto 6GT/s(48GB/s) of data while the DDR3 sticks at 2400MHz will transfer only about 2.4GT/s(19GB/s).

 

[tweakboy]

Good thread. Inform!!!!! marketing bums!