CL9 vs CL 7/8?

Dea924 · 24 Apr 2011 at 20:05

whats the difference between the two?.. im told by a friend that cl9 is "crap" and the lower the number the better the ram

cmndr_andi · 24 Apr 2011 at 20:16

Yea, the lower the timing the better the performance. However, in most applications the difference between DDR3 RAM at CL9 and C7 (with the same frequency) is very small (especially if you are mainly gaming) and the price difference is often steep. Hence why most buy CL9 and spend the money on a better graphics card or CPU (where the money will provide a much larger increase in performance).

Krislord · 24 Apr 2011 at 20:37

This article provides a detailed test of various RAM speeds and latency settings. I went for a 4GB kit for about £50 (CAS 7) however this was when SB was only just launched so information was scarce. If i was choosing now i'd just get some CAS 9.

http://www.bit-tech.net/hardware/memory/2011/01/11/the-best-memory-for-sandy-bridge/1

Dea924 · 24 Apr 2011 at 22:24

yeah when i order on tuesday i was going for the xms cl9 corsair stuff. i think the 8gb offer is on o.c's .. its tempting for £30 more than 4!

Kaeo · 25 Apr 2011 at 07:00

Yeah, by the sounds of it, you probably know a lot more about RAM timings by reading that one article than the person that told you CL9 timings are "crap"

No difference in real world usage.

setter · 25 Apr 2011 at 11:27

+1 for no noticeable difference in real world usage. My ocz reaper kit is rated at 7-7-7-24 1T, but when testing my overclock i have it slackened out to 9-9-9-27 2T.

Dea924 · 25 Apr 2011 at 13:53

i dont really know a great deal about the timings and such, i changed mine to something and they work fine, but generally i just slotted them in and away i went lol.

SeeKified · 26 Apr 2011 at 11:46

The difference per memory request is a couple of nanoseconds, so no, you won't notice. Definitely a better choice to spend those extra pennies on a fancier graphics card or something along those lines.

deusexlumina · 26 Apr 2011 at 11:48

bought some cas8 stuff over the cas9. I know there's not much difference but i just want the best quality ram i can afford i guess.

SeeKified · 26 Apr 2011 at 13:46

I fancy boys said:
bought some cas8 stuff over the cas9. I know there's not much difference but i just want the best quality ram i can afford i guess.

Yeah, well, I bought Corsair TWINX C2 sticks for my current S939 system, so... I get what you mean.

I like my toys even though it's silly. xD

EggCustard · 26 Apr 2011 at 19:42

Theoretically CL9 otherwise known as CAS 9 is worse than CAS 8 or CAS 7 but in practise then in most cases you won't notice any difference at all. Only software that's very memory intensive (i.e. reads and write to memory all the time - encoding let's say) will benefit. The gains however are minute compared to the money you sometimes have to splash out for the lower CAS RAM modules out there (especially Corsair).

Memory frequency is far more important than memory timings.

SeeKified · 27 Apr 2011 at 11:27

For example, PC-3200 DDR1 at CL2 has an open-page read latency of 10ns. PC3-12800 DDR3 at CL8 also has 10ns. CL7 gives you 8.75 and CL9 gives you 11.25. This is put very simply, but it's a rough idea. DDR3 has many other benefits though and obviously has more clocks to work with. Still, it's nanoseconds and won't be picked up by our sluggish reflexes.