How much will CAS Latency effect performance?

[Awesomlego]

I have been looking at RAM for my new build and am wondering how much CAS will affect gaming and everyday performance. There is a set of amazing looking ram with a CAS of 16 and a set of decent looking ram that has accents thta don't match my system with a CAS of 14. Both are same price and speed. Which should I go with?

 

[greens]

14 ALL DAY.

CAS is actually kind of more important than speed, but its the combination of the two that is most important!

Lower CAS, Higher Frequency, is the key to RAM.

 

[geofelt]

A figure of merit for performance is to divide the speed by the cas number. Higher is better.
In your example, the cas 14 ram would be faster.
But, often such ram needs higher than stock voltage and that can impact your overclocking.

Ultimately ram speed for Intel chips means little when looking at real app performance or fps.
Here is a report on ram speed sensitivity:
http://www.silentpcreview.com/article1478-page1.html

 

[Solandri]

Anandtech ran some pretty thorough tests of DDR3 memory of different speeds and latencies. Here are the real-world and gaming test results.

http://www.anandtech.com/show/7364/memory-scaling-on-haswell/3
http://www.anandtech.com/show/7364/memory-scaling-on-haswell/6

Bottom line is there's probably only a 1%-2% speed difference between your two choices. It's not something worth fretting over unless you're doing something like running compression/encryption algorithms for tens or hundreds of hours at a time.

Also note that the results are granular enough that in some cases the ratio of clock speed vs CAS made a bigger difference. That is, going to a slower CAS or clock speed could sometimes yields faster performance due to how well memory accesses interleaved with clock ticks. Unless you're going to buy both, test them extensively, and return whichever ends up being slower, I wouldn't worry about it.

 

[Chugalug_]

CAS latencies and RAM speed for gaming are irrelevant as long as they are relatively tight, and at native speed.
For rendering RAM frequency is more important, but again, CAS latencies play a very small part here, don't seriously take them into account when buying RAM.
As long as it is within reasonable measures, aka under 19 or 20 for 3000MHz RAM and below, you'll be fine.

 

[Tradesman1]

CAS latencies and RAM speed for gaming are irrelevant as long as they are relatively tight, and at native speed.
For rendering RAM frequency is more important, but again, CAS latencies play a very small part here, don't seriously take them into account when buying RAM.
As long as it is within reasonable measures, aka under 19 or 20 for 3000MHz RAM and below, you'll be fine.

___________________

Sorry but 'under 19 or 20' for 3000 DRAM? I don't even remember seeing ANY 3000 at 19-20 and only ultra cheapo DRAM at even 17-18. 15 is the quasi standard with some higher performance at 14 and some at 16. Performance is a combination of CAS and freq (data rate) and can show performance increases depending on how you use you system. You can't see the differences much when simply running benchmarks as it's a doing a single thing, DRAM performance is more apparent when multi-tasking and having multiple apps open (as well as working with large data sets and DRAM intensive apps

Might look at my FAQs and Fiction article, FAQ, page 4

http://www.tomshardware.com/answers/id-2741495/ddr3-faqs-fiction.html

 

[Chugalug_]

Posing a rhetorical question, just saying that as long as they are within a reasonable range that it won't matter than much.
Cheers for the link though!

 

[Tradesman1]

DRAM performance is showing more and more even in gaming as the developers are more and more utilizing DRAM for performance increase, Fallout 4 is a good example. With the price of DRAM being where it is they will continue to exploit this and fine tune the games. And sorry but had to ask as it sounded extremely off the wall as CLs that high are generally tied to 4000-4266 sticks (Mushkin had some early, early 3200 sticks think it was there Redline sticks (never really sold much if any of them 😉 )