Speed and timings

Ken · 18 Jan 2006 at 12:52

Sorry glitch, just a quick question for man_from_uncle.

Hi man_from_uncle,

I am thinking about getting the 3500LL Pro and I think you also have the Asus A8N-SLI Premium. I'm just wondering what cooler you are using as I'm considering the SI-120 and I'm not sure it will fit due to the taller heatspreaders on these Corsairs.

Cheers.

man_from_uncle · 18 Jan 2006 at 13:39

Ken, I am using the Asus A8N-Sli Premium indeed and i had heatsink size concerns too. But that was becuase I went with the Zalman 9500 which i think is even bigger still and it wasn't so much the motherboard i was worried about as the case.

Anyway, in short I don't think you'll have any problems because of either the ram or the motherboard. I can't lie to you, without trying it for myself I can't be 100% sure but I am as sure as I can be without having the parts in front of me. Check the website though, they normally report any fitting problems that are found and your mobo and ram combo is common enough that it will be mentioned if there is a problem. I'm 99% sure you're ok though.

Peetee, I am not entirely sure I understand your question. If you are running the ram at lower speeds using a 166 divider you should (but not definately) be able to get lower timings than if you are running without a divider at 200. The trick is to find the best combination of low timings and high speeds. I am sorry, i doubt i answered your question, but please rephrase it and I'll try again.

Ken · 18 Jan 2006 at 13:42

Cheers mate. Will check Thermalright's site and other forums to see if anyone else is running this setup.

peetee · 18 Jan 2006 at 13:54

i have the 2x512 geil value pc3200, basically on cpuz theres a screen( SPD) with SPD timings and it lists the default timings of 2.5,3,3,6 under the 200mhz frequency, and under 166mhz frequency it lists 2,3,3,5
BUT under the memory tab in cpuz it lists timings, and it says
frequency : 210mhz (take it this is what iv overclocked to currently?)
FSB

RAM: CPU/11 (multiplier by any chance?)
CAS# latency: 2.0
RAS TO CAS : 3
RAS precharge: 2
tras: 6

So are the SPD timings the default programmed into the ram..? and the timings on memory screen what im currently at? i have upped any voltages yet, do you think i could lower the timings+overclock both cpu+memory much more?

man_from_uncle · 18 Jan 2006 at 15:30

I see what you are asking now. Well I don't use cpuz anymore, i prefer everest, but from memory I think you understand it correctly. Your current timings are lower than than the default timings, so that means either you or someone else lowered them (or you used some auto-overclocking program).

If I remember correctly that geil is capable of some very good timings at very fast speeds. But only at 3.5v+. It is a very batch dependant series though, some batches were great, some were only ok. I suspect you can get a lot more out of them but you'll have to be prepared to give it some toasty volts. Personally, i'd try to see what you can do on 3 or less, don't go insane and don't expect a lot more. You might have one of those lucky batches that'll do 2-2-2-5 at 250mhz, but even if you do you don't want to be running it that hot.

I think what i am saying is that you will have to suck it and see, but with voltage i think you'll pull a bit more out of that ram.

peetee · 18 Jan 2006 at 15:51

yea i lowered them myself, im not sure about dividers or whatever they are called, im not too sure that it would be wise to overclock the newcastle core by 50mhz x11

iv boosted the frequency by another 5 now and lowered the tras to 5, its been running stable since my last post, and i never upped the voltage. ill lower my RAS to CAS to 2 next time and overclock a bit more, if its unstable ill up the voltage and see how it copes, since the CPU is overclocking @ same time as the ram should i up its voltage also? if i had the money id invest in a 3700 san diego, that sucks nowhere near as much power as a newcaslte does it and keeps a lot cooler.. hmm

glitch · 18 Jan 2006 at 16:41

Ken said:
Sorry glitch, just a quick question for man_from_uncle.

Crack on mate, the more the merrier!

peetee · 18 Jan 2006 at 16:58

sorry for highjacking your thread by the way :d altho i think its along the same lines and you'll probably understand ram more as its being explained so well to me

man_from_uncle · 18 Jan 2006 at 21:30

Peetee, if you have the time you should experiment with lowering the timings and raising the FSB. You've done well so far but you will probably find that you can't keep improving both at the same time for long.

You will need to raise the vcore pretty soon too because if the CPU is running faster, regardless of whether it is because of the multiplier or the FSB, it will need more volts.

Also, in very basic terms, 'dividers' are the ratio that you run your ram at compared to your FSB (or HTT in AMD64 terms). It is not essential that the calculation for determining CPU speed be 'RAM speed' X Multiplier. You can run your ram out of time with your FSB at certain ratios. Your ram might run at 200, but if you are running a divider of 5:4 then your calculation will be 240 x multiplier. Your ram will be running slower, which will affect your processing speed in real terms, but the inhanced CPU speed will more than make up for it.

Now, on these modern boards dividers are often not represented as simple ratios like 5:4 or 6:5. Instead they are represented as as 200, 166, 133 etc. I really don't know why this approach has been taken but the numbers are themselves a reflection of the comparitive speed that the ram will run at. If you pick 166 as your divider (it's often called something like memory index in the bios) your ram will not actually run that fast, but it will run at a ratio of 166:200 to the FSB. So if you push you ram back up to 200 it will push the FSB to 240. This use of dividers allows you to reach the maximum speed of your processor without the need to run your ram at ultra high speeds.

Note: When people say they want to run '1:1' that means they want their ram to run at the same speed as their FSB.

In the old days with Athlon XP chips, this divider method often had such a negative impact on performance overall (above and beyond the impact of simply lower FSBs) that it was not really worth doing. But the new AMD64 chips are virtually unaffected by the dividers. It used to be the case that you were better off running at 2000mhz without a divider than running at 2400mhz with one, but now things are different.

Anyway i have rambled on long enough. I'll try to pick this up agian tomorrow if anyone is interested.

glitch · 19 Jan 2006 at 00:32

Just as an aside, anyone is more than welcome in this thread. Kudos to all those (especially mfu) who have taken the time to post answers. I'm sure I speak for everyone when I say you have our thanks and respect.

ToLearn · 19 Jan 2006 at 01:38

i got to say thx aswell ive always used intel systems until of late and overclcoking seemed so much more simple on an intel so parts of this thread has helped me a lot

cheers

peetee · 19 Jan 2006 at 10:53

ah right, thanks, im back at uni now till the weekend without my pc so ill keep pushing it when i get back, i wouldnt mind you posting more stuff. One problem i had was how do i find the voltage of my ram? i was going to up that, if i left the settings on auto would the mobo supply it with what it was taking up or would it try to pull it @ more amps which would compromise my system? thanks

man_from_uncle · 19 Jan 2006 at 13:54

Though I don't know exactly how your BIOS works Peetee, it is a fairly good bet that the Auto settings are there to detect what the hardware default is rather than what it thinks you need to make the hardware (in this case ram) run as well as you want.

As for finding out what volts the ram is defaulted/designed to run at your best bet will be the manufacturers website. Having said that pretty much any ram can take 2.9 volts without any real damage (though in most cases this will invalidate the warrenty). I've never actually burnt out any ram at all and i pretty much always run it at 2.9 or 3 volts. Having said that, generally speaking, ram durability is something of an unknown area. It's more often the case that particular batches are prone to dying rather than particular voltages being leathal. It's a fair rule of thumb though that most sticks of ram have a tolorance in the 3.2-3.9v region and once you pass that point you will slowly but surely destroy it.

man_from_uncle · 19 Jan 2006 at 20:57

I was just reading through a few previous posts I made to check for mistakes and I just spotted an absolute doozy. In post number 11 I said that you should raise vcore by no more than 0.5v to cater for the 9% boost in overall CPU speed from PC3200 to PC3500. I meant to say 0.05. Do not under any circumstance add half a volt to what is already going through your CPU. YOU WILL FRY IT.

man_from_uncle · 19 Jan 2006 at 20:59

Out of interest Glitch, are you a philosopher?

glitch · 19 Jan 2006 at 21:00

A digital one, yes.

man_from_uncle · 19 Jan 2006 at 21:02

I just looked at the website........ it doesn't look like any philosophy website I know.

I am actually a non-digital philosopher. Sadly few people really do much philosophy these days......

Jimbo Mahoney · 20 Jan 2006 at 08:37

man_from_uncle said:
I just looked at the website........ it doesn't look like any philosophy website I know.

I am actually a non-digital philosopher. Sadly few people really do much philosophy these days......

Majorly OT, but what sort of philosophy interests you?

man_from_uncle · 20 Jan 2006 at 09:55

All sorts. But I did my postgrad on Moral Intuitionism. It's the theory (in briefest terms possible) that the prime source of moral knowledge is our intuition.

Jimbo Mahoney · 20 Jan 2006 at 11:36

man_from_uncle said:
All sorts. But I did my postgrad on Moral Intuitionism. It's the theory (in briefest terms possible) that the prime source of moral knowledge is our intuition.

Hmm, that's interesting.. The only thing I may have in common in that case is owning (and enjoying) the book 'Man, the moral Animal' by Robert Wright. Have you read it?

I'm more interested in the biological / evolutionary aspect of society, so I guess I'm more of a sociobiologist than a philosopher.