Memory timings need guidance

klif-e · 17th August 2003, 1:15 PM

on the ABIT nF7-S the memory timings in expert mode are

(Row Active Delay) - ( RAS-to-CAS delay) - (Row-precharge delay) - (CAS latency time)

At present I am able to do 7-3-3-2 and 5-3-3-2 seemingly stable at 400Mhz dual channel using Corsair XMS3200 Cas 2

My question is what is better, what am I aiming for?
That is which component of the memory timing equation has the most impact on actual useable bandwidth?

I have been told 5-2-2-2 would be very nice, but I don't think I can get it stable even at 2.7 vdimm.

How much vdimm is too much vdimm for Corsair?

Oblong Cheese · 17th August 2003, 1:19 PM

As long as you can run CAS2 (or lower) then your memory will be speedy. I'm not quite sure what effect the other values have on the memory bandwidth.

turanga · 17th August 2003, 3:14 PM

XMS3200 usually does 5-2-2-2 but I guess you got some lesser sticks. A higher tRAS is better for Nforce2 boards, and I found that I get optimal bandwidth at 10-2-2-2.

Surge · 17th August 2003, 3:21 PM

Quote:

Originally posted by klif-e

How much vdimm is too much vdimm for Corsair?

Set VDIMM to 2.9 in BIOS, it should give you around 3V actual. That's completely safe for any DDR RAM, and will get you the most out of your RAM without voltmodding.

Kabal · 18th August 2003, 1:34 AM

Quote:

Originally posted by klif-e
I have been told 5-2-2-2 would be very nice, but I don't think I can get it stable even at 2.7 vdimm.

6-2-2-2 is faster than 5-2-2-2 in 3dmark for me.

Tenoq · 18th August 2003, 4:49 AM

Quote:

Originally posted by Kabal
6-2-2-2 is faster than 5-2-2-2 in 3dmark for me.

Likewise. Someone mentioned somewhere that if the sum of the first three (2,2,2) is equal to the last (6), your ram will work slightly faster (something to do with not waiting for commands?).

Anyway, so you could try 6-2-2-2, or 8-3-3-2, if u don't want to overvolt. That said, I think Corsair recommends you run their RAM at a 2.8V anyway.

Dr Kildare · 18th August 2003, 9:25 AM

I've found 2-2-2-11 is good too...

Dropbear · 18th August 2003, 12:09 PM

Quote:

Originally posted by Surge
Set VDIMM to 2.9 in BIOS, it should give you around 3V actual. That's completely safe for any DDR RAM, and will get you the most out of your RAM without voltmodding.

Is this good advice?????

Sorry but my mum told me not to believe everything I read on the internet

Anyone got any qualms with that advice? is it going to SERIOUSLY increase the termal output of the dimm to run it that high?

Dr Kildare · 18th August 2003, 12:29 PM

Alright I just did some basic testing using the memtest86 outputs - all readings confirmed...
Interesting results...

2-2-2-1: N/A
2-2-2-2: 1511 (MB/s)
2-2-2-3: 1511
2-2-2-4: 1511
2-2-2-5: 1511
2-2-2-6: 1538
2-2-2-7: 1538
2-2-2-8: 1538
2-2-2-9: 1538
2-2-2-10: 1565
2-2-2-11: 1565
2-2-2-12: 1595
2-2-2-13: 1565
2-2-2-14: 1538
2-2-2-15: 1511

anthony256 · 18th August 2003, 12:30 PM

Quote:

Originally posted by Dr Kildare
Alright I just did some basic testing using the memtest86 outputs - all readings confirmed...
Interesting results...

2-2-2-12: 1595

Very interesting. I'm runnign 6-2-2-2, I might mess around with 12-2-2-2.

Mal · 18th August 2003, 1:40 PM

Quote:

Originally posted by Dropbear
Is this good advice?????

Sorry but my mum told me not to believe everything I read on the internet

Anyone got any qualms with that advice? is it going to SERIOUSLY increase the termal output of the dimm to run it that high?

Thats an acheivable volatge for good DDR.

If things get a bit hot direct a fan over the dimm slots.

I have deleted quite a few off topic posts.

Cheers,
Mal

Lombers · 18th August 2003, 4:38 PM

On the NF7-S I would recommend timings of either 5-2-2-2 or 11-2-2-2.

As for Vdimm, Corsair (from memory) rate the speed of their sticks with a voltage from 2.5 - 2.9V. So it's safe to crank the voltage up higher, tho I don't recommend any higher than 3V for day to running. Generally, you won't see a massive increase going higher than 2.9V anyway, most sticks tend to top out around there.

17th August 2003, 1:15 PM	#1
klif-e Member Join Date: Jun 2001 Location: Melbourne, Victoria, Aust Posts: 759	Memory timings need guidance on the ABIT nF7-S the memory timings in expert mode are (Row Active Delay) - ( RAS-to-CAS delay) - (Row-precharge delay) - (CAS latency time) At present I am able to do 7-3-3-2 and 5-3-3-2 seemingly stable at 400Mhz dual channel using Corsair XMS3200 Cas 2 My question is what is better, what am I aiming for? That is which component of the memory timing equation has the most impact on actual useable bandwidth? I have been told 5-2-2-2 would be very nice, but I don't think I can get it stable even at 2.7 vdimm. How much vdimm is too much vdimm for Corsair? __________________ Games Box Coolermaster CM690, Corsair HX620, ABIT IP35 Pro, Intel Q6600@3Ghz, 8Gb Corsair XMS2 6400C5, Crucial M4 256GB, ATI 4870 1GB Factory OC, 1 x Dell U2711, Pioneer Blu-Ray Drive, Logitech X530 5.1's, Logitech MX Revolution HTPC Silverstone LC17B Case, Corsair HX520, ASUS P5E-VM-HDMI, Intel C2D E8400@3Ghz, 2Gb Corsair XMS2 6400C5, ATI 3650, FusionHDTV Dual Express, 74Gb Raptor, Pioneer Blu-Ray Combo Drive, Xbox360 HD-DVD Addon Last edited by klif-e; 17th August 2003 at 1:17 PM.

17th August 2003, 1:19 PM	#2
Oblong Cheese Member Join Date: Aug 2001 Location: Brisbane Posts: 9,831	As long as you can run CAS2 (or lower) then your memory will be speedy. I'm not quite sure what effect the other values have on the memory bandwidth. __________________ My Website \| My Computers \| Grado Labs Alessandro MS-1, Shure SRH-840, Topping TP30

18th August 2003, 9:25 AM	#7
Dr Kildare Member Join Date: Jun 2001 Location: Melbourne Posts: 3,877	I've found 2-2-2-11 is good too... __________________ Notebook: Apple 15" MacBook Pro 2.4GHz (Penryn) File Server: Dell PowerEdge SC430 3.4GHz (Presler)

18th August 2003, 12:29 PM	#9
Dr Kildare Member Join Date: Jun 2001 Location: Melbourne Posts: 3,877	Alright I just did some basic testing using the memtest86 outputs - all readings confirmed... Interesting results... 2-2-2-1: N/A 2-2-2-2: 1511 (MB/s) 2-2-2-3: 1511 2-2-2-4: 1511 2-2-2-5: 1511 2-2-2-6: 1538 2-2-2-7: 1538 2-2-2-8: 1538 2-2-2-9: 1538 2-2-2-10: 1565 2-2-2-11: 1565 2-2-2-12: 1595 2-2-2-13: 1565 2-2-2-14: 1538 2-2-2-15: 1511 __________________ Notebook: Apple 15" MacBook Pro 2.4GHz (Penryn) File Server: Dell PowerEdge SC430 3.4GHz (Presler)

18th August 2003, 4:38 PM	#12
Lombers Feed Me! Feed Me! Join Date: Jun 2001 Location: Melbourne Posts: 4,026	On the NF7-S I would recommend timings of either 5-2-2-2 or 11-2-2-2. As for Vdimm, Corsair (from memory) rate the speed of their sticks with a voltage from 2.5 - 2.9V. So it's safe to crank the voltage up higher, tho I don't recommend any higher than 3V for day to running. Generally, you won't see a massive increase going higher than 2.9V anyway, most sticks tend to top out around there. __________________ You must always push the limits, because if you never fail, you will never succeed. Overclockers Australia Folding@Home Team Founder Overclockers Australia Folding@Home Team Dedication Award

17th August 2003, 3:14 PM	#3
turanga Member Join Date: May 2003 Posts: 621	XMS3200 usually does 5-2-2-2 but I guess you got some lesser sticks. A higher tRAS is better for Nforce2 boards, and I found that I get optimal bandwidth at 10-2-2-2.