Do I really need CAS 2?

JDCentral

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Jul 14, 2004
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If i'm going to oveclock an Athlon XP Mobile to say... 2.6 Ghz :) will a quality stick of ram with CAS timings of 2-2-2 really be necessary (Crucial Ballistics, to be specific). The price premium for that extra 0.5 ns is really excessive. I could get a quality stick of 2.5 for much less.
 

vrbaba

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Jul 17, 2003
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no! IMO, the extra premium u pay is def. not worth the extra performance u get. its very minimal and varies greatly with ur other components in the system. 2.5 is much better than 3, but 2 is not much better than 2.5. go with a quality 2.5 and you will come close to ur expected performance boost.
 

shoRunner

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Nov 8, 2004
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Originally posted by: vrbaba
no! IMO, the extra premium u pay is def. not worth the extra performance u get. its very minimal and varies greatly with ur other components in the system. 2.5 is much better than 3, but 2 is not much better than 2.5. go with a quality 2.5 and you will come close to ur expected performance boost.


how is 2.5 much better than 3, yet 2 is not much better than 2.5....the difference is the same. if you want to get the most out of your overclocking then keeping your FSB and CPU at a 1:1 is better than asynchously, though how much better varies.
 

JDCentral

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Jul 14, 2004
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As my situation is, the ASUS A7N8X only supports DDR400 (200Mhz FSB), so if I'm running at anything more than the 200 Mhz FSB (Edit: or whatever the limit of my RAM is), I'm going to need to use something other than 1:1, correct?
 

vrbaba

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Jul 17, 2003
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Originally posted by: JDCentral
As my situation is, the ASUS A7N8X only supports DDR400 (200Mhz FSB), so if I'm running at anything more than the 200 Mhz FSB (Edit: or whatever the limit of my RAM is), I'm going to need to use something other than 1:1, correct?

bump...
im looking for a similar answer... i need to overclock my cpu, should i or not use a divider firstly...or just ramp up the voltage?
i will be using dual channel...how does a divider affect performance...pros and cons?
 

JDCentral

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Jul 14, 2004
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Here's how (I beleive) it works:

Your system runs it's FSB at frequency X... but the proc/RAM doesn't necessarily HAVE to run at the same frequency, so you stick in a 'multiplier' or divider, which multiplies or divides your FSB by Y. (So... proc w/ multiplier of 12 and a FSB of 200 will run at 12*200=2.4 Ghz... if the same system has a RAM divider of 1:1, then the ram will run at DDR400 (200Mhz)).

Although, I'm not exactly sure how upping the voltage helps - I'm really curious, actually.

Personally, I'd go with multipliers/dividers before changing the voltage - the multipliers and stuff are just affecting the 'timings' of the device, while the voltage increase will physically effect the component (putting more stress/temperature on it).
 

shoRunner

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Nov 8, 2004
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to overclock you do one of 2 things(or combination) to achieve a higher speed change the multiplier(many processors have this locked) or increase the FSB(or HTT) speed. Unless you change your memory divider it will default to a 1:1. Meaning that when you change the FSB greater than 200mhz the memory will as increase the same amount. If your memory can't take 210mhz then you will have to run a divider(5/4,2/1...etc) to lower the memory speed.

this is a very basic over view of course, and i'm sure i may have missed things as i am no expert in overclocking.

increasing voltages should be done VERY carefully as it would be the only real way to damage your components. If you up the voltage on your ram you may want to have some sort of active cooling on it or be sure it is able to take the voltage you are giving it
 

mshan

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Nov 16, 2004
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I own an Asus A7N8X v2 Deluxe and read that the max fsb people were achieving on that mobo was ~ 220 fsb.
 

JDCentral

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Jul 14, 2004
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Yeah... increasing the voltage increases the amount of stress on the components involved. It's really 'running the gauntlet'. The gates were designed to handle a certain voltage, and although you can push more current through them, this builds up 'pressure'. Which is dissipated in the form of heat.

Personally, I'm not going to try to OC my ram. I'll use dividers to keep the FSB around 200 Mhz.
 

JDCentral

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Jul 14, 2004
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Originally posted by: mshan
I own an Asus A7N8X v2 Deluxe and read that the max fsb people were achieving on that mobo was ~ 220 fsb.


http://www.asus.com/prog/spec.asp?m=A7N8X%20Deluxe

They list supported FSB up to 400Mhz.

Not all Socket A procs will be 'up to the challenge' however - many run at FSB as low as 133Mhz, as I recall (and I think some of the Barton cores run at 400Mhz FSB, but correct me if I'm wrong.. or if they're actually dual or quad pumped, or whatever).

EDIT: You need to change the jumpers to switch to FSB 333/400 Mode: http://www.asus.com/products/mb/socketa/a7n8x-d/jumper.htm
 

vrbaba

Diamond Member
Jul 17, 2003
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Originally posted by: shoRunner
to overclock you do one of 2 things(or combination) to achieve a higher speed change the multiplier(many processors have this locked) or increase the FSB(or HTT) speed. Unless you change your memory divider it will default to a 1:1. Meaning that when you change the FSB greater than 200mhz the memory will as increase the same amount. If your memory can't take 210mhz then you will have to run a divider(5/4,2/1...etc) to lower the memory speed.

this is a very basic over view of course, and i'm sure i may have missed things as i am no expert in overclocking.

increasing voltages should be done VERY carefully as it would be the only real way to damage your components. If you up the voltage on your ram you may want to have some sort of active cooling on it or be sure it is able to take the voltage you are giving it

yes, i believe the intel p4 will be locked. Is it easy to unlock or I cant unlock it?
So heres what I collect...If i cant unlock it, I will be upping the fsb on my cpu, then once I reach 200, I will run th divider at 5:4..and keep upping the cpu fsb...until stability is reached??
 

guilhermemourao

Junior Member
Jun 5, 2005
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the difference of 2.5 to 2 in cas ltency is about 3%+-...it doesn´t worth for the difference...
In the socket A, the nforce 2 chipset requeres the 1:1...it doesn´t runs well in another divisor....
with some value memory and some increase in the voltage(Vmem), you can have the CPu running 1:1 with the memory in the maximum of the chipset, that is about 220~230...
only for extreme overclock and Intel and AMD64 chipsets that the Low latency worths...
 

JDCentral

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Jul 14, 2004
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So, with my NF2 board, I'm pretty much forced to use a 1:1 divider?

That kind of pisses me off, b/c I'm restricted to chips with a FSB of 200 Mhz, as the top ram is DDR400... this seems kind of stupid?
 

JDCentral

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Jul 14, 2004
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What memory, though?
Have you done all sorts of fun OCing/Voltage adjustments on the memory?
 

Fern

Elite Member
Sep 30, 2003
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Originally posted by: JDCentral
If i'm going to oveclock an Athlon XP Mobile to say... 2.6 Ghz :) will a quality stick of ram with CAS timings of 2-2-2 really be necessary (Crucial Ballistics, to be specific). The price premium for that extra 0.5 ns is really excessive. I could get a quality stick of 2.5 for much less.

I've run Cas2.0, 2.5 and 3.0 in my OC'd rig. I don't notice a diff in gaming performance at all.

As far as I can tell, the only benefit to expensive ram is when shooting for a high FSB OC. If you start with Cas2.0 sticks, you'll get more FSB headroom by dropping the Cas to 2.5

As my situation is, the ASUS A7N8X only supports DDR400 (200Mhz FSB), so if I'm running at anything more than the 200 Mhz FSB (Edit: or whatever the limit of my RAM is), I'm going to need to use something other than 1:1, correct?

Negative. You always want to use 1:1 (actual some report better bench performance with 5:5 or 6:6)

But otherwise, the way your post reads there is confusion about the purpose of the divider. You seem to say the divider is for running a diff mobo FSB and ram FSB. The divider is for running the ram and CPU at diff speeds. Not the mobo & ram.


So, with my NF2 board, I'm pretty much forced to use a 1:1 divider?

That kind of pisses me off, b/c I'm restricted to chips with a FSB of 200 Mhz, as the top ram is DDR400... this seems kind of stupid?

Seems like more confusion....

FSB 200 = DDR400. They are exactly the same thing??

BTW: No need to fear voltage increases unless you get extreme. Voltage adjustments are an integral part of OCing

WHAT ARE you trying to accomplish? Please tell us, then we can tell you how to achieve (and can cut through the confusion).

Fern_
 

JDCentral

Senior member
Jul 14, 2004
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Yes.. I understand all of those things :)

From my perspective, the mobo is what provides the FSB, which is MULTIPLIED for the CPU, and DIVIDED for the RAM... thus, the FSB is on the mobo. Confusing ?

Also.. I know DDR400 is fsb 200 (200X2=400).

I'm not really sure what I'm trying to accomplish, yet ;-)

I'm just asking questions, and weighing all of my options. I want to make a top-notch Socket A system to use as a server/media pc.

Overclocking seems to be an integral part of that.

On the RAM side of things: it looks like an OCZ-somethings is in order (DDR 400)... the price difference between Value and Performance isn't much, so I'll probably jump for the Performance.
 

Fern

Elite Member
Sep 30, 2003
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I'm not really sure what I'm trying to accomplish, yet ;-)

I'm just asking questions, and weighing all of my options. I want to make a top-notch Socket A system to use as a server/media pc.

Overclocking seems to be an integral part of that.


May I suggest then, that the first place to start is finding the highest FSB your mobo/ram can reach stably. Use a lower multi on CPU to take it out of the picture.

After that, keep increasing your multi to find the highest OC you CPU can take.

That the typical sequence for getting the best results.

Fern