Uhoh - Athlon XP performs worse when memory is faster than cpu bus?

SagaLore

Elite Member
Dec 18, 2001
24,036
21
81
I just happen to run across an article that stated Athlon XP setups sometimes run slower if the memory isn't synchronous with the cpu. I just bought an NForce2 Ultra 400 and Mushkin dual 2x256 DDR400 (cas 2.5)(PC3200) ram. My cpu is an Athlon XP 1700 which only has a 266 fsb. :(

I guess I should have gotten the Kingston HyperX 2x256mb DDR333 at 2-2-2-5-1 at the same price.

I suppose 3 years from now when it's time to rebuild again, I could just buy an Athlon XP 3200 with 400fsb and it will seem like a whole new machine. :p
 

Matthias99

Diamond Member
Oct 7, 2003
8,808
0
0
Also, unless you explicitly overclock the RAM with a divider, it will normally run your RAM at the 'right' speed (with a 1:1 ratio with the FSB). DDR is backwards compatible.
 

m4ch0dude

Senior member
Jan 16, 2005
220
0
0
I guess I should have gotten the Kingston HyperX 2x256mb DDR333 at 2-2-2-5-1 at the same price.

Or better yet, you could have gotten DDR266 for an even lower price, since you got 266 fsb :p
 

SagaLore

Elite Member
Dec 18, 2001
24,036
21
81
Originally posted by: m4ch0dude
I guess I should have gotten the Kingston HyperX 2x256mb DDR333 at 2-2-2-5-1 at the same price.

Or better yet, you could have gotten DDR266 for an even lower price, since you got 266 fsb :p

Yea I know. :( I've spent the last 3 years engulfed in networking with work, school, and training, that I've become incredibly rusty with today's hardware. I spent several sleepless nights researching all of the parts I was going to get and after ordering, I'm still finding out new stuff that would have helped in my decisions - and it's even outdated technology so there's no excuse for my ignorance. :frown:

I just checked newegg and buying PC2100 ram would have only saved me maybe $20 for standard ram. That Kingston HyperX with the low latency was a good buy, I should have just stuck with that, I was so close to getting it. Then maybe I could have overlocked the cpu to fsb of 333 without it blowing up. I have never overclocked.

What is New Egg's return policy? Maybe I'll ship the Mushkin back and get the Kingston... I have a thermalright sk7 with my xp 1700, and I just ordered some Artic Silver 5... think I can get it to 333 without it smoking?
 

2Xtreme21

Diamond Member
Jun 13, 2004
7,044
0
0
Don't bother returning it.

The PC3200 will run at DDR266 speeds if your overall FSB is 266 and allow for a lot of overclocking room. You will not see any performance increase by exchanging your PC3200 for PC2100... in fact, you'd probably hurt yourself in the long run if you forsee an upgrade in the near future.

You may just want to buckle down and buy a whole new mobo and cpu. They're not incredibly expensive and if you make a good enough choice (based on your needs), you'll have even more future-proofing.
 

Budman

Lifer
Oct 9, 1999
10,980
0
0
Since you got pc3200 cas2.5 I am pretty much certain that it will run at cas2 @ pc2700 speeds. so returning would be a waste of time.

Save your money & just grab a cheap mobile chip when you have extra cash.
 

SagaLore

Elite Member
Dec 18, 2001
24,036
21
81
2Xtreme21: Yep I know it's backwards compatible. I did buy a new mobo, well it's new for me. I know it's outdated but the wish list I originally made was about $1000 for new Nforce3 chipset, Athlon 64, Geforce 6600GT, sata drives, etc. But we just finished paying off a lot of debt and I would rather enjoy the additional cashflow than blow $1000 (before shipping and tax) again. So for under $400 (after shipping/tax), I got an NForce2 Ultra 400 - the MSI Delta2 which had extra features - a new good quality ps to replace the one that died, the ram, and a Radeon 9600 PRO 256mb, and super quiet fans to replace the noisy ones I have.

Budman: Yea that's true. :eek:

What do you mean by "mobile" chip? The laptop version of the A-XP? I'll wait until next year to upgrade the Athlon XP with a 400fsb, because by then they should be a bargain.

So at this point I guess my aim is to get the xp 1700 to a fsb of 333 and the memory down to DDR333 speeds with a latency of 2. Is that what you guys would recommend?
 

Jeff7

Lifer
Jan 4, 2001
41,596
19
81
Originally posted by: Budman
Since you got pc3200 cas2.5 I am pretty much certain that it will run at cas2 @ pc2700 speeds. so returning would be a waste of time.

Save your money & just grab a cheap mobile chip when you have extra cash.

Yeah, those 35W Athlon 2400's are nice things. I've got mine at 2.3GHz, at 1.7v. It could probably do a lot more, but I don't feel entirely comfortable giving it much more voltage than that. Plus, I'd need a bigger heatsink. It already gets a bit warm with an Alpha 8045 and a low-flow fan. Still, it's a very good CPU.

I've also got a 45W 2400, but it'll only do 2.0GHz. But then, the 45W thing is a lot cheaper, at least at Newegg.
 

Cerb

Elite Member
Aug 26, 2000
17,484
33
86
It depends on the app and chipset.
The NF2 chipsets aren't bothered, and you get a slight gaming increase, similar to as if you had dual-channel RAM. SiS, however, suck horribly with async RAM. Dunno about VIA.
 

Shoobie

Member
Feb 20, 2004
115
0
0
Just an FYI, that 1700+ could be a great overclocker. Mine hits 190fsb without a hiccup on an NF7-S (nForce 2 400-ultra). It can go farther, but my cooling isn't great (just bought a Vantec Aeroflow, need to find my thermal paste).
 

SagaLore

Elite Member
Dec 18, 2001
24,036
21
81
Originally posted by: Shoobie
Just an FYI, that 1700+ could be a great overclocker. Mine hits 190fsb without a hiccup on an NF7-S (nForce 2 400-ultra). It can go farther, but my cooling isn't great (just bought a Vantec Aeroflow, need to find my thermal paste).

Isn't the fsb actually 233, so what you mean by 190 is a fsb of 380?
 
Jun 14, 2003
10,442
0
0
aye just keep it,

you could try your hand at overclocking, or just run the ram at DDR266 with fast timings....i think its a win win situation here
 

ViRGE

Elite Member, Moderator Emeritus
Oct 9, 1999
31,516
167
106
Originally posted by: SagaLore
Originally posted by: Shoobie
Just an FYI, that 1700+ could be a great overclocker. Mine hits 190fsb without a hiccup on an NF7-S (nForce 2 400-ultra). It can go farther, but my cooling isn't great (just bought a Vantec Aeroflow, need to find my thermal paste).

Isn't the fsb actually 233, so what you mean by 190 is a fsb of 380?
The AXP FSB is double pumped, so when we talk about the base speed of 266, it's actually 133mhz, with two transmissions per cycle. So yes, Shoobie would mean "380mhz", though most BIOSs go by the base clock speed and would list 190mhz.
 

SagaLore

Elite Member
Dec 18, 2001
24,036
21
81
Originally posted by: ViRGE
Originally posted by: SagaLore
Originally posted by: Shoobie
Just an FYI, that 1700+ could be a great overclocker. Mine hits 190fsb without a hiccup on an NF7-S (nForce 2 400-ultra). It can go farther, but my cooling isn't great (just bought a Vantec Aeroflow, need to find my thermal paste).

Isn't the fsb actually 233, so what you mean by 190 is a fsb of 380?
The AXP FSB is double pumped, so when we talk about the base speed of 266, it's actually 133mhz, with two transmissions per cycle. So yes, Shoobie would mean "380mhz", though most BIOSs go by the base clock speed and would list 190mhz.

So if his 1700+ fsb was overclocked to 190 with no problems, then I shouldn't have an issue getting it to 166, correct? Doing so, I would have to lower the multiplier to keep cpu the same or slower.

I just read a quick article on overclocking the Palomino, looks like I need to fill in some pits and use some kind of conductive material to connection those "bridges"? Bummer.
 

Cerb

Elite Member
Aug 26, 2000
17,484
33
86
Palomino != overclocker.
~1.7GHz was the highest Palominos went. You could get close to 2GHz with some overvolting, but that doesn't seem wise.
 

ViRGE

Elite Member, Moderator Emeritus
Oct 9, 1999
31,516
167
106
Originally posted by: SagaLore
Originally posted by: ViRGE
Originally posted by: SagaLore
Originally posted by: Shoobie
Just an FYI, that 1700+ could be a great overclocker. Mine hits 190fsb without a hiccup on an NF7-S (nForce 2 400-ultra). It can go farther, but my cooling isn't great (just bought a Vantec Aeroflow, need to find my thermal paste).

Isn't the fsb actually 233, so what you mean by 190 is a fsb of 380?
The AXP FSB is double pumped, so when we talk about the base speed of 266, it's actually 133mhz, with two transmissions per cycle. So yes, Shoobie would mean "380mhz", though most BIOSs go by the base clock speed and would list 190mhz.

So if his 1700+ fsb was overclocked to 190 with no problems, then I shouldn't have an issue getting it to 166, correct? Doing so, I would have to lower the multiplier to keep cpu the same or slower.

I just read a quick article on overclocking the Palomino, looks like I need to fill in some pits and use some kind of conductive material to connection those "bridges"? Bummer.
Shoobie doesn't make it clear what he did to his 1700+, so I can't really respond to that. If it's a Tbred core, he could have easily overclocked it completely(i.e. not dropping the multiplier), pushing it to ~2.1ghz. As for the bridges, you're on your own there; it's been forever and a half since the normal XP has been the in thing for overclocking, and I don't remember what the rules are for dinking with the bridges. At the very least, if you can drop the multiplier, everything should work fine if you want to take advantage of the faster FSB that your RAM allows.