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View Full Version : Higher Frequency? or Lower Latency... which is better?


RangerDave
03-08-05, 07:23 PM
hey guys i was looking for new memory.... but i cant find anything that really impresses me... i was looking at this.. OCZ 1Gb PC4200 DDR Performance Dual Channel Series (2 x 512Mb) (OCZ5331024PFDC-K) - Features double the cooling surface area on the heat sink - Timings: 3-4-4-8
and looked okay but then again the timmins where so high. i was wondering will the increased frequency make up for the higher timings? what do i want more off a higher frequency, or a lower latency? btw what ever i get im matching the system bus with it :) on my athlon 3200+ :)

TimoneX
03-08-05, 07:36 PM
If you're going for a board that can provide 3.3+ vdimm then look at some OCZ VX, Value VX, or Twinmos TMSP. Wonderful performance on the A64.

{AG}Sgt.Stryker
03-08-05, 07:48 PM
I asked the same question here (http://www.ocforums.com/showthread.php?t=364523) and then later posted a link on this subject here (http://www.ocforums.com/showthread.php?t=369584). Frankly, I don't think it makes a whole lot of real world difference within a certain range. In other words, higher speed can offset slower timings and vice-versa. It depends on the application. I have found in the games I play that timings have a little more impact than speed. Thus I run my RAM at 5:4 to enable the 2-2-2-5 timings (see sig).

stang8118
03-08-05, 07:50 PM
Me personally, i like tight timings with a divider and a high FSB :)

Eldonko
03-08-05, 09:09 PM
I like max FSB possible and looser timings :P

Shuzzy
03-08-05, 09:44 PM
3 words:

-bandwidth
-bandwidth
-bandwidth

:)

TimoneX
03-08-05, 11:01 PM
Bah bandwidth is teh overrated and it yields diminishing returns as it increases. I'll take the tight timings & 250-270 over DDR600+ and mid to sloppy timings anyday of the week.

Just look at the choices the guys that top the ORB are making.

VX
VX
VX

Wonder why. :D

hitechjb1
03-08-05, 11:30 PM
I think there is no clear 1 way answer to this question. It depends on a few things such as
- how high the motherboard, CPU can go in terms of FSB or HTT (for A64)
- what Vdimm voltage is available and willingness to supply such high voltage on memory modules (and memory controller)

E.g. for A64
If motherboard, CPU and memory can run above 300 MHz HTT with 2.5-3-3-x 1T, then high frequency memory modules such as TCCD are preferred with 2.8 - 2.9 V (nice and cool). Such high frequency can overtake the low latency advantage of 2-2-2-5 1T at around 250 MHz.

If system can run between 260 - 300 MHz HTT, and if high Vdimm 3.3 - 3.5 V is an option and is chosen to be used, then the BH-5/UTT (typically 250-260 MHz 2-2-2-5 1T) low latency memory run at a ratio can perform better than high frequency memory at 280 - 300 MHz 2.5-3-3-x 1T.

For system under 260 HTT, and if high Vdimm 3.3 - 3.5 V is an option and is chosen to be used, then the BH-5/UTT run low latency memory at 1:1 can perform better than other memory modules.


These posts attempt to quantify the tradeoff between memory frequency and latency on performance, including some test results between UTT and TCCD type of memory, ....

Memory frequency and latency tradeoff (http://www.ocforums.com/showthread.php?s=&postid=3475627#post3475627)

How much frequency increase is needed to break-even with low latency (http://www.ocforums.com/showthread.php?s=&postid=3476357#post3476357)

Testing UTT and TCCD memory modules in Winchester and DFI NF4 Ultra-D setup (http://www.ocforums.com/showthread.php?s=&postid=3514143#post3514143)

TimoneX
03-08-05, 11:44 PM
Well spoken as ever hitechjb.