How to optimze RAM/FSB Ratios?

[Overspeed]

I've been reading up on the benefits of running RAM & FSB 1:1. First off, my RAM is 2x2GB Mushkin PC2-8000. So a FSB of 1000 or 500 depending on how you look at it. My E8400 is a 1333FSB CPU ... 9x multiplied 333FSB quad pumped to achieve 3.0Ghz. For me to get a 1:1 ratio, I need to severly underclock the RAM to 333FSB. Of course I bought faster RAM to get faster speeds but doesn't look like its a good match for the CPU. So then I thought why not change to 8x multiplier @ 375FSB (not a huge increase, but better). PC will not boot period at those settings and voltages are not overclocked, everything auto. 7x430FSB will not work either. Then I came to think ... while technically i'm not overclocking the GHz, I am overclocking the CPUs overall FSB. The E8400 is set to run at 1333FSB and by setting to 8x375FSB its now running at 1500FSB. So i'm not sure what I need to do here. This is an aspect of overclocking I am uncertain about. While in all scenarios i'm only getting 3.0Ghz, the overall FSB is being pushed and I'm curious if what i'm trying to do is even possible. I can't overclock beyond 3.0Ghz at this time until I take care of my motherboards NB & circu-pipe heat issue. I want to get my RAM working as fast as it can ... and still maintain a 1:1 ratio. Am I missing something? Perhaps my understanding of overclocking was wrong in that it's not about pushing the overall GHz, its about pushing the FSB of the CPU ... or maybe its both. In the end, for now I just want to get my RAM operating as fast as possible, and keep 1:1. How might I achieve this? Is my understanding of overclocking flawed?

 

[repoman0]

Have you raised any other voltages at all? Like the NB or VTT (?)

I've never overclocked a 775 system BTW, so I'm not entirely sure on what I'm doing - but from reading forums, it seems like people usually need to raise NB volts to get a decent FSB. I was pretty good with AMD 939 though, had a few 3GHz + Opties on air/water alike, so I'm not completely retarded on the subject

edit: But I am certain that what you're trying to do is possible. I'll be attempting something similar with my setup - 400x8 with as low volts as possible, 1:1 with my DDR2-800 RAM - 3.2Ghz is plenty for now. You just have to figure out how to stabilize it. (volts, timings, etc - can't help you there!)

 

[Dangman]

While yes, you won't notice an actual performance increase from anything higher than a 1:1 ratio, you can leave your RAM at DDR2 1000 speeds while the FSB at 333Mhz if your motherboard supports that config (3:5 ratio).

Also, it's been shown that a higher FSB doesn't provide a major performance increase. So even though with your FSB at 1500Mhz and your multi at 8, your 3Ghz E8400 will still perform about the same as a 9x multi and 1333Mhz FSB E8400 at 3Ghz. In fact, if your FSB was at 2000Mhz but still at 3Ghz, performance will still be the same as 1333Mhz 3Ghz.

 

[repoman0]

While yes, you won't notice an actual performance increase from anything higher than a 1:1 ratio, you can leave your RAM at DDR2 1000 speeds while the FSB at 333Mhz if your motherboard supports that config (3:5 ratio).

Also, it's been shown that a higher FSB doesn't provide a major performance increase. So even though with your FSB at 1500Mhz and your multi at 8, your 3Ghz E8400 will still perform about the same as a 9x multi and 1333Mhz FSB E8400 at 3Ghz. In fact, if your FSB was at 2000Mhz but still at 3Ghz, performance will still be the same as 1333Mhz 3Ghz.

Wouldn't his higher RAM speed make the performance difference? Even though ram doesn't matter that much with C2D it should still make a little difference right?

And, am I missing something - why would you ever use the extra volts, heat, and looser timings to run the RAM higher than 1:1 if it doesn't offer any performance benefit? Makes no sense to me

 

[Dangman]

Wouldn't his higher RAM speed make the performance difference? Even though ram doesn't matter that much with C2D it should still make a little difference right?

The only difference he'll see is an increase in synthetic benchmarks like 3DMark or whatever. No actual real-world increase in games.

And, am I missing something - why would you ever use the extra volts, heat, and looser timings to run the RAM higher than 1:1 if it doesn't offer any performance benefit? Makes no sense to me

The OP's RAM is rated for DDR2 1000 speeds. So he won't have to loosen any timings nor increase the voltage just to run the RAM at DDR2 1000 speeds. But some people do run the RAM higher than 1:1 simply for the hell of it and the ePenis.

A few articles to read:
http://www.madshrimps.be/?action=getarticle&number=4&artpage=1965&articID=472
http://www.legionhardware.com/document.php?id=628

 

[repoman0]

The only difference he'll see is an increase in synthetic benchmarks like 3DMark or whatever. No actual real-world increase in games.

The OP's RAM is rated for DDR2 1000 speeds. So he won't have to loosen any timings nor increase the voltage just to run the RAM at DDR2 1000 speeds. But some people do run the RAM higher than 1:1 simply for the hell of it and the ePenis.

A few articles to read:
http://www.madshrimps.be/?action=getarticle&number=4&artpage=1965&articID=472
http://www.legionhardware.com/document.php?id=628

Well, he could probably undervolt, underclock, and tighten the timings and have the exact same performance, according to the articles.

Interesting articles though! I guess I won't even worry about keeping my RAM at 800MHz or more.. though I might still do the 400x8 thing because I like even numbers..

 

[BinarySynapse]

I'm going to try to address this bit by bit. I'm not trying to be an asshole, but just want to clarify some things which might make your efforts easier on you.

I've been reading up on the benefits of running RAM & FSB 1:1.

The only real benefit to 1:1 is when you're overclocking by a large amount to avoid passing the RAM's rated speed. Older systems (e.g. socket A) had problems with anything other than 1:1, but today's systems don't.

First off, my RAM is 2x2GB Mushkin PC2-8000. So a FSB of 1000 or 500 depending on how you look at it.

Memory speed and FSB are two different thigns. Your memory runs at 500MHz, but since it's DDR the actual data throughput is doubled to 1000MT/s.

My E8400 is a 1333FSB CPU ... 9x multiplied 333FSB quad pumped to achieve 3.0Ghz.

Similar to your ram, your frontside bus runs at 333MHz and transfers data at four times that. The processor gets its final speed from the 333MHz, not the quad-pumped speed (1333)
.

For me to get a 1:1 ratio, I need to severly underclock the RAM to 333FSB. Of course I bought faster RAM to get faster speeds but doesn't look like its a good match for the CPU.

Faster RAM only really benefits overclocking. The CPU can only handle so much data, and your ram would only be "waiting" on the CPU to send or get ready for the next set of data.

So then I thought why not change to 8x multiplier @ 375FSB (not a huge increase, but better). PC will not boot period at those settings and voltages are not overclocked, everything auto. 7x430FSB will not work either.

Upping your FSB is a gradual process. 1MHz at a time. This way you can get a feel for the limits of your motherboard.

Then I came to think ... while technically i'm not overclocking the GHz, I am overclocking the CPUs overall FSB.

The GHz? Overall FSB? Ouch. You overclock the CPU, and measure it in GHz, you don't overclock GHz. There is also no such thing as an overall FSB. The FSB is only a link between the CPU and the rest of the system. Once the processor gets its speed set, the FSB is largely irrelevant to the function of the CPU...except to feed it something to crunch on.

The E8400 is set to run at 1333FSB and by setting to 8x375FSB its now running at 1500FSB. So i'm not sure what I need to do here. This is an aspect of overclocking I am uncertain about. While in all scenarios i'm only getting 3.0Ghz, the overall FSB is being pushed and I'm curious if what i'm trying to do is even possible. I can't overclock beyond 3.0Ghz at this time until I take care of my motherboards NB & circu-pipe heat issue.

Your CPU running at 3.0GHz isn't going to directly affect how hot your northbridge gets. Upping the speed of your FSB however does. The NB runs at whatever speed the FSB runs at.

I want to get my RAM working as fast as it can ... and still maintain a 1:1 ratio.

Again, not much point since with 1:1 the CPU is getting data as fast as it can take it. Anything more is just gravy running off the plate and into your lap.

Am I missing something? Perhaps my understanding of overclocking was wrong in that it's not about pushing the overall GHz, its about pushing the FSB of the CPU ... or maybe its both. In the end, for now I just want to get my RAM operating as fast as possible, and keep 1:1. How might I achieve this? Is my understanding of overclocking flawed?

Should be clear as mud now... which is better than tar I guess.

 

[Overspeed]

Ryan, that was an excellent guide, thank you very much!