Finding RAM Timings?

stickroad

stickroad

stickroad

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Ok i have an AMD 3400+ haven't overclocked the CPU yet but i can easily do that but when it comes to the RAM im very confused.

Ive got CPU-Z and when i go to Memory its got:

CAS Latency
RAS to DAS Delay
RAS Percentage
Cycle Time (TRAS)
Bank Cycle Time (TRC)
Command Rate

Not sure what all these mean.

Where are the RAM timings for instance 4-4-4-12?

If someone could help me out ill be very grateful, thanks
 
stickroad said:
Ok i have an AMD 3400+ haven't overclocked the CPU yet but i can easily do that but when it comes to the RAM im very confused.

Ive got CPU-Z and when i go to Memory its got:

CAS Latency
RAS to DAS Delay
RAS Percentage
Cycle Time (TRAS)
Bank Cycle Time (TRC)
Command Rate

Not sure what all these mean.

Where are the RAM timings for instance 4-4-4-12?

If someone could help me out ill be very grateful, thanks
Click to expand...
m8 what mobo do you have? That would really help in answering your question/s :)

& had a look here?

Lol @ above 2 posters :mad:
 
Yes ive read that sticky i still dont understand which ones what for the RAM Timings.

Could you please explain what settings i have to change that affect the Ram Timings for instance 6-8-7-15 and how i would change it to say 5-5-5-12.

Not saying my motherboard and RAM will take it i just want to know how to change these numbers.

So which one in the CPU-Z Memory settings refer to the Numbers 5-5-5-12

Thank you
 
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It really would help if you post your spec. Do you have a Athlon 64 3400+ or a Sempron 3400+? Is it socket 754, 939 or AM2?

The first number is usually CAS Latency and is the most important as it makes the biggest difference when you change it. Change it too much however and you may not be able to boot and will have to reset the cmos. Around a 5% performance increase when changed to a lower value.

Next is RAS-CAS delay. About a 2% increase if changed to a lower value.

Next is Ras Precharge, Again about 2% increase.

Last Is RAS Active, again another 2% increase.

The next one you need to tweak is the command rate. 1T is better than 2T and makes quite a bit of difference performance wise.

These are the main ones you need to worry about. Most of the other settings make little difference. Timing is mainly important only in socket 754 and 939 DDR1 AMD rigs. With DDR2 i believe bandwidth is more important than timings.

Have a read of this article as it explains what each setting actually does. Memory Timings Explained . All of the changes are usually done in the bios.
 
Ah im still really confused ive read that article still dont get it.

Its saying the Ram Timings are 2-2-2-6 thats really good right? from the article that is

This is what it reads in CPU-Z under Memory.

Frquency - 200.9mhz
FSB/DRAM - CPU/11
CAS Latency - 3.0 clocks
RAS to CAS Delay - 3 clocks
RAS Precharge - 3 clocks
Cyclye Time (TRAS) - 8 clocks
Bank Cycle Time (TRC) 11 clocks
Command Rate - 2T
DRAM idle Timer - 16 clocks

So if i got this right the Ram Timings would be as Follows.

3-3-3-8 would that be right?
 
What you need to do is go into your bios and manually alter your timings (think I understand what you mean).

It is most likely that your bios is defaulting to the 3-3-3-8. You need to alter these to 2-2-2-6.

Give that a go.

If you plan to clock your processor, this is where you may have to loosen these timings to get more speed out of your modules, or run your memory on a divider. Cross that bridge though when you come to it. :)
 
Yes. That's right.

Your fsb is 200.9mhz with a multiplier of 11x giving you cpu a speed of 2.2ghz. That means it's a Clawhammer with 1024kb of level 2 cache. I have one in my old pc. :D

I am betting you can change your timings in the bios quite easily. I have 2x512mb sticks of Crucial value pc3200 which is supposed to run at 3-3-3-8. However i was able to tighten the timings up to 2.5-2-2-5 and also change the command rate to 1T. They run those timings with no voltage increase. I am not saying that yours will do the same but it's certainly worth a try. You will certainly be able to alter the command rate to 1T anyway.

Do one change at a time starting with the command rate, save changes and reboot. If it boots into windows with no problems then restart and change the TRAS from 8 to 5. Save changes and reboot. If ok then restart and change the Ras Precharge to 2. Save changes, reboot. If ok restart and change the Ras-Cas from 3 to 2. Save etc. Finally the Cas latency from 3 to 2.5 save and reboot. I did it in reverse as the Cas latency makes the biggest change. If it does'nt work try changing the dram voltage from 2.6 to 2.7v or even 2.8v, but no higher. If you want to be brave do them all at the same time but if it does'nt boot then you won't know which change is causing it.

You should also run memtest/prime/orthos when all the changes are done to make sure everything is stable.
 
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stickroad one of the best RAM threads is this at ABXzone
BTW you cannot see my photos there like a guest.
CAS Latency should be 2.5 or 3.0, start setting 3.0 in the beggining.
In every step run RAM benchmarks to see how much you gain/lose of performance.
 
Ok ive changed the Timings and they are now set to:

2-2-2-6, at 133mhz.

I tried to raise the Memory to 266mhz at the same timings but it crashed, so in theory if i changed the timings to say 3-3-3-7 it would have a chance to run at 266mhz is that correct?

One more thing because i understand it now.

I will be getting a new comp soon the E6600 and getting the Crucial DRR2 Tenth Anniversary stuff and the timings are 3-3-3-12.

Why are my timings on a DRR lower?
 
Hehe, I usually do it the other way round by doing the CAS first, as if it's going to fall over, this will usually be the first hurdle where it will. :)

Just saves time really!
 
stickroad said:
Ok ive changed the Timings and they are now set to:

2-2-2-6, at 133mhz.

I tried to raise the Memory to 266mhz at the same timings but it crashed, so in theory if i changed the timings to say 3-3-3-7 it would have a chance to run at 266mhz is that correct?

One more thing because i understand it now.

I will be getting a new comp soon the E6600 and getting the Crucial DRR2 Tenth Anniversary stuff and the timings are 3-3-3-12.

Why are my timings on a DRR lower?
Click to expand...
Yes pretty much so, you may get 266 out of the modules, you might not. Overclocking is trial and error with a dash of luck :D

The latencies on DDR2 are higher because the speed is higher, in the same way that you have to loosen your timings to get higher speeds out of your DDR1 modules. DDR2 also works on a lower voltage :)
 
Change the Cas latency to 2.5 and raise the voltage to 2.7v and then try to raise the fsb. By the way it should'nt be running on a divider. Do you have a setting to set it to 200mhz or ddr 400.

DDR2 generally has higher timings as tighter timings are not so important as bandwidth. Timings are tightening up now though. It was not so long ago that they were really slack.
 
Yep i could change the Memory to 400 and about this Ram Divider?

And in the SPD tab its got the Timings table down Below and its got two different frequency's 166mhz and 200mhz and then two diffrent Timings?

Mind explaning? thanks
 
PC3200 is DDR400 (Double Data Rate) so 200mhz (the second one in CPU-z) is 200x2=400mhz. The first one is for pc2700 ram which is DDR333 166x2=333mhz. At a lower speed the memory will run tighter timings as a rule. What you are seeing in CPU-z are the default timings stored in a chip on the memory called the SPD. It will run these timings automatically. They are however usually quite slack and almost always you will be able to tighten them up.

Some people use a divider such as 166 to downclock the ram before overclocking. This artificially sets the ram to run at a lower speed than what it is designed to do. This is because, to overlock you raise the fsb. This in turn makes the ram run faster and in turn you will have to slacken off the timings. If you run the ram on a divider then you can keep the tight timings that socket 754 and 939 needs.

For example.
I want to overclock my 4000+ from 2.4 to 3.0 ghz. It runs a 12x multiplier of 200mhz. 12x200=2400mhz. (2.4ghz). To get it to 3.0ghz i would run it at a fsb of 250mhz x12=3000mhz. (3.0ghz). This also makes the ram run at 250mhz or ddr500. As it is ddr400 it may not even run at that speed even with slack timings (mine does :D ) so you put the ram on a divider of ddr333 (166mhz). It still raises the speed of the ram but it does not exceed it's designed speed of 200mhz (ddr400). It will run at 192mhz when the fsb is actually set to 250mhz. This still gives me more or less the same bandwidth and my tight timings but i can still overclock the processor.
 
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pastymuncher said:
PC3200 is
Click to expand...
If you divide the number 3200 with 16 --> 200 MHz = the FSB.
PC4400 --> 4400/16 = 275 and so on.
stickroad Vdimms up to 3 Volts are not dangerous for brand name RAM modules.
 
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