Memory Bandwidth vs. Latency Timings

[Rubicund]

Hi Everyone,

I'm building a gaming PC and I'm wondering what is the difference between DDR3 1600 ram with high timings as compared to 1333 ram with lower timings?


Here is an example:

Brand G.SKILL
Series Ripjaws Series
Model F3-12800CL9D-4GBRL
Type 240-Pin DDR3 SDRAM
Tech Spec
Capacity 4GB (2 x 2GB)
Speed DDR3 1600 (PC3 12800)
Cas Latency 9
Timing 9-9-9-24-2N <-------------------------
Voltage 1.5V
ECC No
Buffered/Registered Unbuffered
Multi-channel Kit Dual Channel Kit
Heat Spreader Yes


v.s.

Brand G.SKILL
Series Ripjaws Series
Model F3-10666CL7D-4GBRH
Type 240-Pin DDR3 SDRAM
Tech Spec
Capacity 4GB (2 x 2GB)
Speed DDR3 1333 (PC3 10666)
Cas Latency 7
Timing 7-7-7-21 <-------------------------
Voltage 1.5V
ECC No
Buffered/Registered Unbuffered
Multi-channel Kit Dual Channel Kit
Heat Spreader Yes


Thanks in advance.

~Rubicund

 

[ekoostik]

If you're up for some reading I can point you to some articles that are informative and should help you answer that question.

Most of the articles agree the differences between each step up in RAM is often marginally noticeable, and outside of a benchmark it is difficult to say whether or not you would even notice the difference. And the cost difference can add up fast. But there is a difference and a decision has to be made when putting a computer together, what's best for you as the builder and user of the pc. The best advice I got from these forums was buy the best RAM that fits your budget, if you find yourself stretching things just to get 'better' RAM that's probably money better spent on other components.

Most of the focus of these articles is on frequency. But they test different levels of timings too so are still applicable to your question. I find the following 2 articles to be helpful:
http://www.tomshardware.com/reviews/memory-scaling-i7,2325.html
http://www.anandtech.com/memory/showdoc.aspx?i=3589

Both of those articles were written about the i7 9xx / 1366 socket chips. I haven't kept track of any articles testing the difference on AMD though I could probably dig one up. I also haven't seen a lot of articles specifically focused on RAM speeds on the P55 platform. However, Tom's has had two.

First up: http://www.tomshardware.com/reviews/core-i7-870-1156,2482.html
I didn't care for the way results are presented, to me it's not as clear cut as it could have been. I think it points out there's little difference between marginally slower and faster RAM but the way the results are shown leave room for individual interpretation. Also the test page (and the URL) states that they used an i7 870, but in the opening they (still!) say testing was done with an i7 860 . Still worth a read.

And finally, they did a review of value RAM you may also find interesting: http://www.tomshardware.com/reviews/ddr3-4gb-p55,2462.html