needhelp with timings

K, I'm finally making the switch to ddr from rdram. I watn to learn about timings. I know they have the sticky at the top which explains all the things in the bios, but i want a thing solemly for ddr timings.

For example, with rdram it was x4 or x3. DDR is a lot harder to adjust if you compare it with rdram.

i see timings like 2-2-6-2-t1 or something like that, just making an example. The only thing i know is the 1st 2 which is the cas latency. I know some people will raise the cas latency up to 2.5 for a higher overclock. But what about thre rest of the line, the 2-6-2-t1. What do those do and how should i adjust those accordingly with the cas latency for a higher overclock without taking a huge performance hit? Also, i just bought the ic7-g board, and i see like memory things wher ei can do 1:1 3:2 and 5:4. What does this have to do with the 2-2-6-2-t1 thing? Thanks.

roYal said:

Also, i just bought the ic7-g board, and i see like memory things wher ei can do 1:1 3:2 and 5:4. What does this have to do with the 2-2-6-2-t1 thing? Thanks.

Click to expand...

those are fsb/sdram ratios

for example....if youve got a 200fsb set and a 1:1 ... the fsb and RAM will be running at 200....(800 fsb actual because its quad pumped....and 800...for the RAM if you're running DDR400 in dual channel

for 3:2:.....i.e. 300fsb and 200 RAM....but actually 1200FSB/ 800 for the RAM

for 5:4.......i.e. 250FSB and 200 RAM.....actual...1000FSB/800 for the RAM

-TriX

Re: Re: needhelp with timings

-=TriX-R4-KidS= said:

those are fsb/sdram ratios

for example....if youve got a 200fsb set and a 1:1 ... the fsb and RAM will be running at 200....(800 fsb actual because its quad pumped....and 800...for the RAM if you're running DDR400 in dual channel

for 3:2:.....i.e. 300fsb and 200 RAM....but actually 1200FSB/ 800 for the RAM

for 5:4.......i.e. 250FSB and 200 RAM.....actual...1000FSB/800 for the RAM

-TriX

Click to expand...

The actual should list as 400 dual channel. It would be nice if we had ram capable of 800Mhz, we settle for two 400Mhz sticks running together to get the same bandwidth of one 800.

Hammer

roYal said:

What does this have to do with the 2-2-6-2-t1 thing? Thanks.

Click to expand...

those are the ram timings. your correct on one of the 2's being the cas timing.

i'll use my settings as an example
6/3/3/2.5

the 6 is the Cycle Time (otherwise known as Tras)
the two 3's are RAS Precharge and RAS to CAS delay
the 2.5 is the CAS timing.

for all these numbers lower is faster. the cycle time is always the highest number, the cas is always the lowest (or should be).

when relaxing the timings (relaxing the timings would be setting them to higher settings to achive a higher overclock or to gain stability) you want to keep the RAS Precharge and CAS Delay the same if possible (2/2 3/3). the CAS timing you seem to know about, try to keep this as low as you possibly can. the Cycle Time has a less impact on performance then the other timings but it also doesn't provide much headroom when raising it (meaning you won't get much more of an overclock by setting this higher).

my motherboard doesn't have the T1/T2 setting so i skipped it. this is the command rate timing, usually default's to T2, setting it to T1 provides a little performance but usually at the cost of about 3-4Mhz (from my limited expirence).

this probably isn't the best explaination but i'm still learning it myself. if anything i said is wrong then please correct me.

so will an ic7-g let me adjust the 6/3/3/2 settings or just the memory ratios 1:1 3:2 5:4 or will it let me adjust both? IF it's both, my god am i goign to be lost while trying to adjust. I don't want to fry the memory or anything, this stuff is sure expensive.

i don't know what settings the IC7 has but if you set the ram timings to agressive all it will do is put out errors or fail to boot (in which case you'll have to clear the CMOS). the VDimm (ram voltage) is what will fry the ram.

the 1:1 3:4 4:5 ..... setting just determins when the ram speed will be compared to the fsb. a 1:1 ratio will be like 200Mhz fsb/200Mhz ram, 3:4 would be 200Mhz fsb/266Mhz ram. a 1:1 ratio is prefrable (also, the first number is usually the fsb and the second is ram).

everyone had to figure this out at one point, it's not easy but you'll get the hang of it.

roYal said:

K, I'm finally making the switch to ddr from rdram. I watn to learn about timings. I know they have the sticky at the top which explains all the things in the bios, but i want a thing solemly for ddr timings.

For example, with rdram it was x4 or x3. DDR is a lot harder to adjust if you compare it with rdram.

i see timings like 2-2-6-2-t1 or something like that, just making an example. The only thing i know is the 1st 2 which is the cas latency. I know some people will raise the cas latency up to 2.5 for a higher overclock. But what about thre rest of the line, the 2-6-2-t1. What do those do and how should i adjust those accordingly with the cas latency for a higher overclock without taking a huge performance hit? Also, i just bought the ic7-g board, and i see like memory things wher ei can do 1:1 3:2 and 5:4. What does this have to do with the 2-2-6-2-t1 thing? Thanks.

Click to expand...

The order of the ram timings depends on the board. I list mine as 7-2-2-2 because that is the order my NF7's Bios lists timings. The first is RAS or cycle time...the second is RAS-to-CAS delay...the third is Row Precharge...the fourth is CAS latency. I'm not exact sure what order yours is listed but I know the "6" is RAS. Do a search to find out the meanings of all these timings.

The next thing you mention is the 5:4 & 3:2. These are your front side bus (FSB) to Memory Bus ratios. Let's say you have a new 800Mhz fsb processor, you would set the ratio to 4:4. The true FSB is 200Mhz and the Ram bus would sink up at 200Mhz. Since the FSB is quadpumped (transfers data 4 times per clock cycle) You would say that your FSB is 200MHZ x 4= 800Mhz. Your DDR ram is only double pumped so it ends up being 200Mhz x 2 = 400Mhz. The DDR ram is then run in Dual Channel so you now have two 400Mhz channels giving you the bandwidth of single channel 800Mhz.

Now lets's say you overclocked your FSB 250Mhz (1000Mhz), you can set your ratio to 5:4 to maintain your 400Mz ram bus while the FSB is overclocked. You have to experiment with different ratios to find the combination of FSB & memory bus speeds that work for you.

Hammer