512mb DDR 400 vs. 1GB DDR 333 2

[JAG14]

Hi all, I was recently give a 512mb Stick of DDR333 for nothing (very nice of them.)
I have put it into my system and set the BIOS Memory Clock to run at 333Mhz where it used to be 400Mhz with one stick of DDR400 512mb.
As daft a question as this may sound, am I getting a better performance from 1Gb at 333 than 512mb at 400?
Is there really a noticable difference between 333 and 400?
and should I just go out and buy a second 512mb at 400 instead?

Thanks in advance..

JaG

[tt]'Very funny, Scotty... Now Beam down my clothes.'[/tt]
​

 

[franklin97355]

Unless you are doing things that are real memory intensive you will not notice the difference. The larger amount of memory will be more significant than the speed difference in most cases.

The answer is "42"

 

[paparazi]

The answer!!!!! really depends on your hardware.
Most older systems ie: Socket A /Intel 478 were best when the ram set to run synchronously with the CPU.
For instance: an Athlon XP2500 which has a front side bus of 333 needs PC2700 DDR333.
Installing DDR400 would result in the memory defaulting to it's ideal but lower setting of 333, so no benefit! from fitting the faster memory type.

So as I said! it depends on your hardware.
Which is??????

Martin

We like members to GIVE and not just TAKE.
Participate and help others.

 

[cdogg]

As paparazi said, it heavily depends on your hardware, particularly the motherboard and CPU make/model.

On many systems that have DDR400 memory, the CPU is using a multiplier that relies on the bus speed to be 200MHz. For example, a 2.0GHz Athlon XP with 400MHz FSB would be using a 10x multiplier to get to full speed. If you lower the bus to 166MHz, then the CPU will only run at 1.6GHz.

Note: The frontside bus (FSB) runs at half of the rated speed than is listed for the CPU and memory (and 1/4 of the FSB speed listed on Intel CPUs). This is the "true" speed. DDR technology sends twice as much data during each clock cycle, which is why they say it's 400MHz memory. It's not really moving at 400MHz. So, a 166MHz FSB is what DDR333 memory uses.

Intel's FSB is able to send 4 times as much data per clock cycle, which is why you see speeds listed like 800MHz.

~cdogg
"Insanity: doing the same thing over and over again and expecting different results." - Albert Einstein
[tab][navy]For general rules and guidelines to get better answers, click here:[/navy] faq219-2884

 

[JAG14]

So..... If I have a Asus P4-800S MoBo and a P4 2.8Ghz CPU with the above configuration? How does that one work?

TIA

JaG

[tt]'Very funny, Scotty... Now Beam down my clothes.'[/tt]
​

 

[cdogg]

Well, it still depends on the exact model of the P4 you have. Your motherboard supports P4s with 400MHz, 533MHz, and 800MHz. So you need to know which speed your CPU requires.

I'm guessing it's 800MHz, which is the case for most of the 2.8GHz P4s out there. And if that's the case, then you don't want to use DDR333, as it will force you to have a slower FSB which like I showed lowers the CPU speed.

~cdogg
"Insanity: doing the same thing over and over again and expecting different results." - Albert Einstein
[tab][navy]For general rules and guidelines to get better answers, click here:[/navy] faq219-2884

 

[JAG14]

Cdogg.

Thanks for the response..

So, what would be the best memory configuration for me then?

TIA

JaG

[tt]'Very funny, Scotty... Now Beam down my clothes.'[/tt]
​

 

[cdogg]

For now, it would be best to take out the stick of DDR333 and just run 512MB of DDR400.

You can probably sell the stick on eBay for the same price you can buy another DDR400 stick on eBay.

~cdogg
"Insanity: doing the same thing over and over again and expecting different results." - Albert Einstein
[tab][navy]For general rules and guidelines to get better answers, click here:[/navy] faq219-2884

 

[paparazi]

As cdogg points out, it depends on the P4 CPU model but my guessing would be you are "most likey" to have a Prescott core processor, which has a 800front side bus.
What that means is this particular CPU needs PC3200 (DDR400) for it to run without restriction.

Martin


We like members to GIVE and not just TAKE.
Participate and help others.

 

[JAG14]

OK thanks guys,

As it happens, I Know that the CPU I have is a Prescott Core, and I've just spoken to someone who'll straight swap the 333 for a 512mb of 400. Handy eh?

Thanks very much for your responses guys, you've been superstars.

JaG

[tt]'Very funny, Scotty... Now Beam down my clothes.'[/tt]
​