CAS latency in RaBit?

Geminiwave

Hey I downloaded RaBit and decided I was gunna screw around a bit...my question is: should I mess with RAM timings at all? I noticed settings for CAS latency and such and was just thinking about messing with those.

anyone else tried it yet?

me972

I played with it in its former version 1.3 and in most cases if you "fuck up" the timings either the card wont boot or you'll get artifacts in dos mode as soon as you reboot. or the system will hang during heavy graphics.

not to mention the damage you might be causing the memory if its not cooled corectly.

if you want to be on the safe side download some XT bios files and see the timings in no way are you to use tighter timings then an XT for a PRO/SE card.
in case of an XT card...ou might lower them a little ...but thats taking some risks... just make sure you have a PCI card around in case you need to reflash.

rgds
me972

Geminiwave

Yours is running at XT speeds.

besides mine has the R360 chip which is nice.

thanks for the info though. I wasnt gunna do super ram timings but I wanted to see about cas latency since on my system RAM it makes huge differences depening on CAS latency.

digitalwanderer

There is a difference in the Pro & XTs CAS timings?

Sorry for the stupid, but I got the wrong card when I bought my X800 pro VIVO and just got the RMA yesterday and since it was the right card and RaBit came out with X800 support so I took it as a sign and flashed it to 16 pipes 500/540.

I just pulled the clock numbers out of me butt. I didn't want to run full XT speeds 'til I knew she could, but I was pretty sure she could handle 500/540 no problem. (And she seems to like it just peachy, and so do I. 8) )

Geminiwave

She?

do you stroke the back of her GPU to see how hot she is? ;-) I know I do that with my baby.

digitalwanderer

For $469us yer damned right I'll personify it!

Mindriot

I downloaded a Pro and a XTPE bios from here:
http://www.techpowerup.com/bios/

This is what I found different:

XT > Pro
Write Latency 1.5 > 1.5
RAS to CAS Read 8 > 7
RAS to CAS write 6 > 4
Row Precharge 8 > 5
RAS Latency 14 > 6
Read/Write turnaround CL+1 > CL+2
Write Recovery 4 > 7
Write/Read turnaround 5 > 1
W/R turn -same bank 5 > 7


It looks like the pro bios has a little tighter settings overall. I guess that is to be expected given that it is operating at a lower clockspeed.

I wouldnt think that loosening the timings would have a major effect. You might loose a couple percent performance per, but gain in max clockspeed.
Tightening it up on the otherhand is anyones guess.

edit: DIGI, you should be able to run the memory @560 if you have 1.6ns ram on the board, since thats the rated speed. The core is the touchy part. I have mine going @ 506/560 n/p in a room with no AC.

No_Style

I tightened some of the timings for my 9800 and I gained about 100 3DMarks in 03.

me972

100 points in 3dmark03 is nothing... run the bench with no changes a few times and you'll get verious scores in that range...


as for tightening the rates on an XT to the PRO's settings might cause the card to reach lower O/C speeds... so theres that to consider aswell..

Mindriot

yeah, but a delta of 100pts in 3dmark is about right for just tweaking memory timings. Thats about 1-3%

No_Style

Yes, I'm aware that the gains are low. I was just mentioning how much of a gain I get. And no, I didn't touch the CAS settings. In fact, that setting shouldn't be touched at all.

me972

I'm not sure how to spell this word but this is what you might call a
negligible mod. hehe

waste of time..

digitalwanderer

Thanks, I do have the 1.6ns ram.

Geminiwave

thats one persons opinion.

some people dont want to overclock though and getting alittle bit of extra performance for free is nice.

Besides I just wanna know what kind of effect these have on the card, thats all.