How MUCH performance difference between CAS2 and CAS2.5 DDR???

I've decided to get one bank of 512MB PC2100 DDR SDRAM with my new system. Checking pricewatch.com, I found that I could get this memory for $55 directly from Mushkin. It is rated CAS 2.5-3-3. After searching their site, I found their 'performance' 512MB memory rated at CAS-2-2-2 latency for $115. This 'performance' memory includes a 'heat spreader.'

I'm building a system with an Athlon XP 1800+ and the yet to be released Soyo Dragon Plus (VIA KT266A chipset). My question is, will I see a significant performance boost by getting the CAS-2 memory? Would it be possible to push the standard memory to CAS-2 (the Dragon board does NOT offer the option to up the memory voltage)? Would I be able to push the 'performance' memory harder when overclocking the system?

I know the question: "Would I get a $60 performance boost?" would be very subjective. But the $60 difference might decide whether I buy a gForce3 (original) at fire sale prices, or opt for the new gForce3 Ti 500.

I would just buy crucial cas 2.5 you can get 2x256mb sticks for about 60.00.
I run 2 x 256 of it at 155fsb cas 2.
I do have the voltage upped to 2.7 from 2.5 if you want to run a high fsb ddr voltage adjustment is really useful.

As far as cas 2.5 and 2 you would only see the difference running benchmarks.

Here is a link to get a discount.

http://forums.overclockers.ws/vb/showthread.php?s=&threadid=41046

Sheesh--only ONE reply so far?

Anyway, I'm also wondering if getting two sticks of 256MB DDR PC2100 memory is better than one stick of 512MB. It's actually cheaper to buy the one stick of 512MB (in most cases). How can one tell the QUALITY of certain brands. I know you can sometimes luck out and get cheap memory that overclocks well, but is there any database to search where I can read reviews?

Also, can 4-way interleave be activated with a single stick?

mbigna said:

Sheesh--only ONE reply so far?

Anyway, I'm also wondering if getting two sticks of 256MB DDR PC2100 memory is better than one stick of 512MB. It's actually cheaper to buy the one stick of 512MB (in most cases). How can one tell the QUALITY of certain brands. I know you can sometimes luck out and get cheap memory that overclocks well, but is there any database to search where I can read reviews?

Also, can 4-way interleave be activated with a single stick?

Click to expand...

I don't know about the 512 stick any better or worse than the 256 stick, but almost eveyone who use crucial is happy with it, I'm able to get my ram setting way up high with crucial(T1, 4way..blabla) Or you might want to gamble on cheap ram, you can and might find it better, who knows.
yeah, you can enable 4 wayinterleav with one stick or ram

With a humble ECS K7S5A 850 Duron box(with the memory running at 133 Mhz, even though the CPU's at 100 Mhz), the difference in Sandra Memory BM's between running Crucial PC-2100 @CAS2.5 and CAS2 is far less than one percent.

With this particular setup, the difference in Sandra Mem BM's between PC-133 @Cas2, and PC-2100 @Cas2 is a whoop de do ~4%.

Which makes the present cost of DDR a MUCH better deal!

In fairness, a KT266A box with FSB and DDR at 133 Mhz with a fast T-Bird or XP in it should reveal a better performance delta. It better!

klosters64a said:

With this particular setup, the difference in Sandra Mem BM's between PC-133 @CAS2, and PC-2100 @CAS2 is a whoop de do ~4%.

Which makes the present cost of DDR a MUCH better deal!

In fairness, a KT266A box with FSB and DDR at 133 Mhz with a fast T-Bird or XP in it should reveal a better performance delta. It better!

Click to expand...

klosters64a--

I'm not sure that you answered my question. I'm still confused when you say that with "a KT266A box with FSB and DDR at 133 Mhz with a fast T-Bird or XP in it should reveal a better performance delta." You were comparing PC-133 memory to PC-2100. Are you saying that you expect no great difference between CAS2 and CAS2.5 PC2100?

Go for the crucial, see sig for my results.

Bump the ?

Is Cas 2.0 significantly faster than 2.5? Is mem speed more of a factor that cas latency? I'm looking at Corsair XMS2400 or maybe the Mushkin CAS2 @ 300MHz but I'm trying to keep an open mind about 2700.

Gee... I heard ppl such as placid saying how they got their Crucial 256mbx2 pc2100 @ cas 2 155FSB.... Once i tried 150 FSB instant blue screen of DUMP MEM DEATH... Even with at 10x150... Cas 2 SDRAM Latency was set to 0... Placid any tips man how did you get yours up there?

Voltages: Vcore__________ DDR VOL______
FSB between CPU_DDR_PCI 4:4:1 or 3:3:1
SDRAM speeds: Auto/Normal/Fast/Turbo/Ultra
Cas Latency: 2 out of 2.5 (ddr mb)
Motherboard:
CPU Brand:
Age of RAM:
FSB: 155
Multiplier:
SDRAM Latency: 0 or 1


Please fill that in Placid!!! THANKS ALOT..
If anyone wants to fill it with similar settings or even better if you have a KG7-R mobo with Crucial pc2100 256mb x 2 of ram fill that

In benchmarks the difference between cas 2.5 and cas2 is the same as the difference between 150 and 166 mhz, at least for me. Anyway its quite a bit.


If you want to know how i got my FSB so high, its all in the northbridge cooling. I put a big heatsink on there, and boom.