Corsair DDR2-800 CAS5 = suicide?

[rwaritsdario]

Ive posted a few threads about my new build and they always recommend me the TWIN2X2048-6400C4 but my budget has become really tight after going for an expesive mobo and liquid cooling.
So far im going for the TWIN2X2048-6400 wich is the same but its CAS5.
Would I really be going wrong with CAS5??
Does the CAS4 offers 35% more performance as the higher price??
Could I somehow chance the timings on the CAS5 to reach CAS4??

My specs:
Asus Crosshair
amd X2 4200+ AM2
MSI 7900GT
250GB WD caviar
OCZ GameXtream 600W

 

[mpjesse]

CAS latencies make very little difference in performance w/ DDR2 memory. CAS5 is fine.

You can always lower the DDR2 clock speed and lower the CAS to 4 if you don't plan to overclock. Most high speed DDR/DDR2 is capable of tighter timings at lower clock speeds.

At any rate, don't worry about it. CAS5 is fine. And if you plan to OC, that CAS 5 corsair is more than enough.

 

[fredgiblet]

Actually AMD CPU's are CAS sensitive. But the CAS 5 RAM should do fine, at 800 Mhz the difference between CAS 4 and 5 is slim.

 

[Crashman]

I'd just get the 5400C4 and overclock it. It goes a little past 800 still at CAS4. In fact, it's probably the same RAM, but without the performance gaurantee.

 

[rwaritsdario]

CAS latencies make very little difference in performance w/ DDR2 memory. CAS5 is fine.

You can always lower the DDR2 clock speed and lower the CAS to 4 if you don't plan to overclock. Most high speed DDR/DDR2 is capable of tighter timings at lower clock speeds.

At any rate, don't worry about it. CAS5 is fine. And if you plan to OC, that CAS 5 corsair is more than enough.

Could I lower the CL to CAS4 while increasing the clock speed a litte bit??
Would I be compromising alot of clock speed overclocking for CAS4??
thanks

 

[rwaritsdario]

I'd just get the 5400C4 and overclock it. It goes a little past 800 still at CAS4. In fact, it's probably the same RAM, but without the performance gaurantee.

Even that the $30 cheaper is tempting I got to think, and if I can overclock the 5400 by 18% to reach the 6400, couldnt I overclock the 6400 by 25% to reach the 8000 speed??

 

[rwaritsdario]

It's what lies underneth those heatspreaders.
What Crashman was telling is that DDR2-667 4-4-4-xx generally uses the same IC as DDR2-800 5-5-5-xx.

You can only get DDR2-1000+ with DDR2-800 4-4-4-xx which you can't afford.

Without minding the timings because ive heard they dont make a very noticiable difference at those speeds. How much do you think I could overclock the speed to with the CAS5 DDR-800??

 

[Crashman]

Around 900MHz, the same as the CAS4 5400.

 

[rwaritsdario]

Around 900MHz, the same as the CAS4 5400.

so basically what youre saying is that I could overclock them like this: (wihtout a warranty of course but mainstreanly)

DDR2-675 CAS4 OC'ed = ~DDR2-900 CAS 4
and
DDR2-800 CAS5 OC'ed = ~DDR2-900 CAS5
??

Is this right or im just talking crazy? sry i have so many questions im not very informed in ram OCing as you can see lol

 

[rwaritsdario]

I think ill just go with the DDR2-800 CAS5, so I get an 800 warranty. But in case I need to skimp ill go for the DDR2-667 CAS4.
By the way, yes, the timings are 4-4-4 on CAS4. thanks alot