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512MB PC3200 DDR or 1GB PC2700 DDR??? Which one?

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SKreme

Technical User
Oct 10, 2004
23
US
I have a laptop with 512MB pc3200 DDR Ram. I found a deal for another 512MB DDR ram for $60. It is PC2700 though which I understand will slow all the RAM down to PC2700. Is it worth it to buy it now, or wait until I find a deal on PC3200. Whats the difference in speed between a 1GB of PC2700 and 512MB of PC3200?
 
Isn't it generally true that the faster the better???

BTW... Further specs are 533 FSB and P4 3.2 GHZ
 
You mean your Manual says that the laptop can use PC2700 AND PC 3200 at the same time? That means you would have to set the FSB to 166. Do you have seperate setups in the BIOS for CPU and memory speeds. You still may get memory sync problems.
 
I guess I was mistaken. I was under the impression that if a processor can handle 3200 it can definitely run anything lower... but I never checked the manual. So I suppose, it only takes 3200 cuz thats what it came with.
 
I apologize. It takes 2700 only. Thanks for everyone's help.
 
Skreme,
Yes, in this case it didn't really matter since PC2700 is what you needed anyway. However for future reference, it is generally recommended that you run memory in synch with your frontside bus to avoid increasing latency and stability problems. When not synched, the BIOS is forced to use a non-optimal "FSB:memory bus ratio", sometimes even where you have to set it yourself.


~cdogg
[tab]"All paid jobs absorb and degrade the mind";
[tab][tab]- Aristotle
[tab][navy]For general rules and guidelines to get better answers, click here:[/navy] faq219-2884
 
Guys!!!! Am I missing something here?

If this is a mobile P4 3.2 533FSB CPU, then surely it can take PC2100 and up? (PC2100 DDR266) which will equate to 4 x 133= 533mhz

So the PC2700 AND PC3200 would actually both be pulled down to PC2100 speeds anyway?
But either way the PC2700 ISN'T slowing anything down and poor SKreme is getting innacurate advice?

Martin



We like members to GIVE and not just TAKE.
Participate and help others.
 
paparazi,
No one really suggested anything. The only real suggestion I saw was to check the manual which seems logical and hardly "inaccurate". Seems like he finally did from his last post.

Second, don't forget that it is possible to run memory out of synch with the FSB. The ratio can be set to run the FSB at 133MHz and the memory bus at 166Mhz or 200MHz, whatever ratios the motherboard supports. I don't recommend it, but it is possible.


So no, I don't think you've missed anything at all.


~cdogg
[tab]"All paid jobs absorb and degrade the mind";
[tab][tab]- Aristotle
[tab][navy]For general rules and guidelines to get better answers, click here:[/navy] faq219-2884
 
It all depends on the motherboard what can be handled. Yes, you can run a 133 clock cpu w/ PC2100, PC2700, or PC3200 speeds if the motherboard allows it.

On the flip side, if the motherboard allows it, you CAN RUN a 200 clock cpu w/ PC2100 or PC2700 memory. I've seen it first-hand running flawlessly.


Regardless, I have never seen any motherboard yet that with a 133 clock cpu forces you to use PC3200 speeds, and I don't believe any exist, which is what Paparazi is getting at.


Lastly, with a 133 clock cpu, it is optimal to run the memory at 166MHz (if the ram is PC2700 or higher), and benchmark tests have confirmed this. I know rule of thumb says match the clocks, but in the case of 133MHz cpu & 166MHz ram, there is a sizable speed increase.
 
How do you change the clock CPU and multiplier on a laptop?
 
dakota,
Think we're straying off too far on a tangent. First of all, the thread originator has already gotten his/her answer. My post (which apparently started this tangent) was just a general statement about how the FSB and memory bus should match. The reason for that was stated in my next post that it "generally" improves stability and reduces latency which is true.

Some benchmarks show hits in performance when you try to run them out of synch, because the increased memory bus speed isn't enough to offset the additional latency in some cases. On the flipside, other benchmarks may show a benefit. Regardless, nothing in that post said that they have to be set that way. Just a general rule of thumb for starting out...


Skreme,
The CPU multiplier is locked out of the box on a CPU. Besides, it's not the multiplier that we're talking about. The frontside bus is what you can adjust. It should be set to 133MHz. Your laptop's motherboard should have an auto adjustment for the memory, which likely should be running at 166MHz (333MHz in DDR terms) if it came with PC2700 memory as you stated. At this point, it would be best to consult your manual and laptop manufacturer's website for further instruction.


~cdogg
[tab]"All paid jobs absorb and degrade the mind";
[tab][tab]- Aristotle
[tab][navy]For general rules and guidelines to get better answers, click here:[/navy] faq219-2884
 
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