new kingmax 512M pc150 cas2@133MHz ?

[radadman]

I had a pair of kingmax 256M pc150 for quite a while and love em! they hit cas2@144MHz no problem. So I just got a pair of the new 512M chips. They can't even hit cas2@124MHz more or less the 133 I want them to run at. I'm forced to run them at cas3. I tried every bios option and still can't boot xp. Soon as I set wpcredit to cas2 windows locks right up. I know i'm not doing anything wrong, did I get a pair of bad chips? I can get up to 156 fsb with cas3 but not even 124 with cas2???

[Placid]

512mb memory tends to be slower (not as high of a overclock) as a 256mb due to the higher chip density and increased capacitance.
If it's a 150mhz stick you might have a inferior sample.

[MadMan007]

Good point about the 512 sticks not being as OC friendly. Re: my topis called "kingmax 512 MB??" maybe 2x256 would have same OCing as a theoretical 512 anyway?

[Placid]

You have to remember the memory is used in banks by the system.
256 and 512 are both double sided and use 2 banks each.
Now think of trying to drive 256 cars thru the same path as 128.
Maybe a bad analogy but it's basically what is happening.

A 128mb is a single sided memory and uses one bank so there is no difference when it comes to 2x128 vs. 1x256 except for the physical extra socket and the traces going to it, then 1x256 is better.

[Ifishsum]

I had a similar problem...got a new stick of 256 Kingmax and it wouldn't do 133@cas2 reliably and would only load windows half the time @148mhz cas3. I RMAed it...it's guaranteed to do 133 cas2 or 150 cas3. I'm waiting for the replacement right now. Most reviews I read indicated that many of these would do 150 cas2 but I have a suspicion that many resellers are culling these better sticks and selling them at a premium price...I saw at least one company that offered them at almost twice the price, tested at 150 cas2. You should at least get what you paid for, 133/2 or 150/3

[radadman]

Yea Maybe I'll RMA em back. I really wanted to run a 1/4 divider and csa2 memory, which these 512 modules won't do. I can hit cas2 @ 115FSB but i'm losing like 40MHz on the FSB and 300MHz clock speed.
Most ram I ever used does only 5-10MHz more with csa3 instead of cas2 How these 512M modules hit 156cas3 but can't post 133/cas2 is beond me!

[murdoch]

Well I have a stick of pre-tested 512 micron from memorysuppliers.com. it was 512 cas3 at 150 or 133 cas2. It did just that. Cas 2 133 with all the tweaks on an o/c cell 800 as well as 150 cas 3. Even did 166 cas 3 with all the tweaks but couldn't get stability in tests. Where as my old crucial by it self couldn't couldn't do the 166 at all. The difference between the ram was that the pc 150 was 6ns where as the crucial was 7.5.When running some ram tests it it reported the ram was 5.5ns. Now this ram is 3 times what i paid 5 weeks ago

[tainice]

Am i the luck one here? my kingmax 256 can hit 155 222, 5/7 on all my boards, and 160 222, 5/7 on my Soyo board....man o man, i never once on spending that 40 dollar get my 256 stick:D Best investment so far.

[radadman]

Wow thats some awesome kingmax! want to trade me?

[tainice]

radaman, dunno if you are just joking or what, but i need it because all my chips are 133 based, so i got to have that ram in order to oc...:)