Lowering Cas??

[Rairun]

Hi
I have Kingston HyperX Ram(2 gb dual kit).This ram is works at max 750 mhz and Cas 4.I'm using Intel 6600 proccesor, so my ram works at 533 mhz.Is it possible to lower Cas latency because i use the ram at a lower speed?
Thanks

(btw i have Asus P5W DH Deluxe mainboard)

 

[slicessoul]

Try it.
If you got crash, hang, or corrupted data, return it to its default speed.

 

[Rairun]

Any suggestions for the ram settings on bios???

 

[Rairun]

I did some changes then system didn't boot up!Even it was impossible to go enter the bios.I had to remove bios battery on mainboard.Now everything is normal.But i won't give up
Does anybody know the proper ram settings for my system?As i mentioned before, i have Asus P5W DH Deluxe,Intel Conroe 6600 and Kingston HyperX DDR2 750(600).Please help me.

 

[Rairun]

Look at the sh.Normally timings of my ram(at 750 mhz):4-4-4-12-1
But they run on my system(at 333 mhz) :5-5-5-15-21
I have to fix this but i don't want to do wrong settings on bios again.I'm waiting for help.

 

[evongugg]

You need to change your memory frequency back to 266 MHZ, then you will get those CAS timings that you want.

 

[Wishjuh]

Hi
I have Kingston HyperX Ram(2 gb dual kit).This ram is works at max 750 mhz and Cas 4.I'm using Intel 6600 proccesor, so my ram works at 533 mhz.Is it possible to lower Cas latency because i use the ram at a lower speed?
Thanks

(btw i have Asus P5W DH Deluxe mainboard)

I don't understand this... I ask this because I'm getting the same configuration end this year (I'm only buying different memory, PC6400\800Mhz memory): why do you have to clock the ram latency down? The E6600 CPU runs @ 1000Mhz fsb... and the memory @ 750...

So I don't understand this sentence: "I'm using Intel 6600 proccesor, so my ram works at 533 mhz"
Why does the ram run at a lower speed while your CPU is running at 1000Mhz fsb?

So according to this info... It's not needed to buy memory with 800Mhz becoz my CPU will not work with it?? Or am I talking bullshit? I'm confused...

 

[Rairun]

So according to this info... It's not needed to buy memory with 800Mhz becoz my CPU will not work with it?? Or am I talking bullshit? I'm confused...

Wrong.You may need a 800 mhz ram if you wanna overclock the cpu.

 

[Wishjuh]

So according to this info... It's not needed to buy memory with 800Mhz becoz my CPU will not work with it?? Or am I talking bullshit? I'm confused...

Wrong.You may need a 800 mhz ram if you wanna overclock the cpu.

Hmm strange... so when I'm not OCing my CPU... it's not needed to buy 800Mhz memory... I always thought that the CPU FSB had to be the same as the Dual Ram memory speed.. like I have now... I now have 2x 512Mb 400Mhz memory (is 800Mhz in total) And my P4 is running @ 800Mhz fsb... I always thought that those values had to be the same to get maximum effect... I quess I was wrong...

So you are saying... that when I put 800 Mhz CL4-4-4-12 memory in my new system... The cas-latency will not be 4 but 5?
Sorry for all the questions but it's really difficult to understand... and I must be certain with this kinda things becoz it's going to cost me alot of money...

 

[The_OGS]

C'mon guys, you gotta grasp the situation here :^)
The Intel Core2 runs 266MHz FSB!
You have heard of double data rate (DDR) right?
Well, Intel CPUs are quad-pumped (QDR) so 266 x 4 = FSB1066 (effective).
Memory running 266MHz (533DDR) is therefore said to be 1:1 synchronous with the 266MHz (1066QDR) FSB.
This speed provides 4200MB/s memory bandwidth - which is why they call it PC2-4200 - and therefore 2 x PC2-4200 in 128-bit (dual-channel) mode provides 2 x 4200MB/s memory bandwidth, which is 8.4GB/s.
This matches the Core2 CPU bandwidth of 8.4GB/s precisely.
Your PC2-5300 memory is rated to run 333MHz (667DDR) and you can see from CPU-Z that this setting is not synchronous, it is 4:5 FSBRAM. This increased speed provides little or no benefit because the increased bandwidth is overshadowed by latencies involved in the 4:5 translation...
It is therefore better to buy PC2-5300 instead of PC2-4200, as you have done, but to run the memory at PC2-4200 speed which is 533DDR.
You can see from the SPD info reported by CPU-Z that this memory will immediately offer 4-4-4-12 timings at the 266MHz speed.
If you increase the memory voltage to 2.0V or ~2.1V I feel certain you could run 3-3-3-9 timings at the 266MHz speed.
Even faster memory will offer even quicker timings, if run at the slower synchronous 266MHz(533DDR) speed.
If you run your memory 1:1 there is another benefit - your memory can run at least 333MHz, so you could increase your Intel FSB beyond 266MHz without any memory worries.
Don't know if this reply has addressed all issues - but I hope this helps.
Ask me for some more specific info if I am able to offer it,
Regards

 

[Rairun]

Thank you very much OGS.Your reply has been very helpful.
Btw, my memory is not 5300 as you mentioned.It's PC2-6000(750Mhz).
Do you really suggest me to increase the memory voltage to 2.0V or ~2.1?!If you really think this won't damage my memory,then i'll do it.
Just one last thing: you gave me four numbers.In bios there are five numbers to set:
Cas# latency 4-->3
RAS# Cas 4-->3
RAS# Precharge 4-->3
Activate to Precharge 12-->9
Write recover time 4-->???????
And thanks again!
Regards
My current configuration:

 

[The_OGS]

There ya go, 4-4-4-12. Did it do that automatically or did you set it manually?
I am only aware of PC2-4200, PC2-5300 and PC2-6400, which are rated 533MHz, 667MHz and 800MHz respectively.
Yours is an interesting speed - it will do 667MHz or less with very good tight timings, but probably still do 800MHz in an AMD AM2 rig.
Anyway 2.0V is not bad and everyone should use it.
The memory requires it but not all motherboards can deliver...
2.1V or more could be tried if 2.0V is not cutting it. You need a modern case with good air movement, then no worries.
I would just enjoy the 4-4-4-12 if everything is set to auto, and there you go. This should run great at 2.0V or even 1.8-1.9V - whatever your mobo can give. My ABit gives 2.0V on 'default' heheh... it's a good one.
But yes, there are many more settings than the big-four commonly quoted in memory advertisements. That's why big-$$ memory will have very tight timings in SPD, so we don't have to fook with it ;^)
But the overclocker, he's not going to set anything to automatic and he doesn't care what's in the SPD LoL, so it's trial & error, push-test-push...
Anyway CPU-Z is giving you the 5th SPD timing specification there, so you can specify those five and then fiddle with the others (or just leave them on auto).
L8R

 

[Rairun]

After i set ram speed to 266, the latency settings didn't change(i checked it out by CPU Z).So i did those timing adjustments manually on bios.
So, do you think that adjusting those settings to 3-3-3-9 will improve system speed very much??

 

[The_OGS]

Yes, 3-3-3-9-12 would be great for you.
This is the way to go with Core2; the alternative is running a 2:3 ratio which would require PC2-6400 @ 800MHz and good memory + high voltage to get tight timings.
Beyond 533MHz, there is no real benefit until 800MHz plus...
667MHz seems not the 'sweet spot' for Core2 (for reasons previously discussed).

 

[Wishjuh]

Yes, 3-3-3-9-12 would be great for you.
This is the way to go with Core2; the alternative is running a 2:3 ratio which would require PC2-6400 @ 800MHz and good memory + high voltage to get tight timings.
Beyond 533MHz, there is no real benefit until 800MHz plus...
667MHz seems not the 'sweet spot' for Core2 (for reasons previously discussed).

So, correct me if I'm wrong, When I put PC6400 memory in my mainboard with the C2D E6600... then I have to OC my cpu fsb to get both values at the same level? Damn I hate it that it is so difficult for me to understand

 

[rwaritsdario]

So, do you think that adjusting those settings to 3-3-3-9 will improve system speed very much??

Its not gonna be night and day but you can always benchmark it.
Run memtest to test for stability.