DDR memory and P4 2.6GHz 800MHz FSB HT question

R

RudeCurve

Banned
I'm helping a friend upgrade an old PC's cpu and memory and have a few questions. The PC is currently running a socket 478 P4/Celeron 1.7GHz 400FSB and DDR266. The motherboard supports up to a P4 3.0GHz with Hyperthreading. It also supports DDR200/DDR266/DDR333. It's listed as only having 400/533FSB support?:???:

So here is my question, I just installed a P4 2.6GHz 800FSB + HypeThreading in the PC and using the same old DDR266 and it's working BUT it says that it is only running at 1.3GHz?:cry: What seems to be the problem? Also will DDR333 memory change anything? Would it be compatible with this cpu?:???:

In My Computer XP it says 2.6GHz and then following that it says 1.3GHz. In System Information it says it's running at 1297MHz, there's no mention of 2.6GHz.
 
From what I've gathered it seems that it's running at 400MHz FSB quad-pumped? This cpu has a 13X clock so it's 100MHz FSB single-pumped = 1.3GHz?
 
oops edit :
i meant pc-3200

ddr2 is usually prefixed with pc2
if your board only supports 200/266/333 (PC1600/PC2100/PC2700)
why did you buy a cpu that need a 800mhz bus (quad pumped 200mhz) ?

if it really wont do 200 you'll have to run it at 166x13 = 2158mhz
still buy 2 sticks pc-3200 not pc-2700 as they are the same price (iirc) and the pc-3200 will probably run at tighter timings at 166mhz than a pc-2700 stick would

what did cpu-z say about your cpu ?
ps: what board do you have
 
Last edited by a moderator:
When I ran the app it said the memory was running at 100MHz as I'd expected. I got this 800MHz FSB P4 before checking the supported FSB speeds, big mistake. Well I just ordered a 533MHz FSB P4 so I'm going to sell this CPU on ebay and try to get some of the money back. Thanks for the help.

Oh I also ordered two 512MB PC3200 DIMMs. I will try to overclock the P4 to 3GHz.
 
Last edited by a moderator:
i doubt you will get 3ghz as that would mean running a 800mhz bus which your pc doesnt support
if you could run at 800 there would be noo need to sell your cpu as you could run it at 2.6

ps: you say your board supports upto a 3ghz p4 did they make 3ghz p4's that didnt run at 800mhz
mine runs at 800mhz

pps: how much does a p4 sell for now ?
 
The motherboard is a CFI CF-968L http://www.mightymicro.com/IC/t_proddetail.mev?process=200002&prodid=10201 which uses the Intel 82845GE + ICH4 chipset. I don't think it supports dual channel mode but that's ok. The BIOS allows me to run the current DDR266 memory up to 130MHz while keeping the PCI bus at 33MHz. I tried it on the P4 2.6GHz and was able to make it run at 1.69GHz instead of the 1.3GHz. With a P4 2.4GHz 533FSB, I could get it to run at 3GHz if the board lets me run the memory at 166MHz. With DDR400 the BIOS might allow close to 166MHz operation.

I got the 2.6GHz P4 for about $20 before shipping.

http://www.starmicro.net/detail.aspx?ID=116

I just ordered this P4 2.4GHz for $21.

http://www.starmicro.net/detail.aspx?ID=111

Intel did make P4 3GHz with 533MHz FSB.

http://www.starmicro.net/detail.aspx?ID=121
 
Last edited by a moderator:
Davros said:
your board must support dual channel p4's need it
Click to expand...

I don't understand. So the P4s need dual channel but the P4/Celerons don't?:???:

It's only running 1 DIMM at the moment with the P4 based Celeron 1.7GHz and it's running at the correct frequency.
 
Last edited by a moderator:
Davros said:
your board must support dual channel p4's need it
Click to expand...

P4's don't "need" dual channel in the way that Davros seemed to insinuate. Let's try to clear some of this mess up:

Rude: You were correct in assuming that the board defaulted to a 400FSB which is why your CPU ran at half speed. You could have possibly overclocked the board to as high as it would go in an attempt to make up for that lack of speed, but the CPU going slowly was a direct result of the board's inability to understand and/or reach the proper FSB.

Dual channel isn't necessary for proper operation, although it's certainly a benefit for the obvious memory bandwidth-performance reasons. Even a modern Core 2 Duo or even Quad processor can run at full advertised clockspeeds without dual channel memory, but again, you're sacrificing memory bandwidth and thus application performance.

Finally, Intel did indeed make a socket 478 / 3.06Ghz / 533FSB / Hyperthreaded processor, in fact that was their first consumer-grade hyperthreaded processor. And it made it's debut on a non-dual channel northbridge design (i845) :)

It won't be a screaming box, but it doesn't sound like they need a screamin' box anyway. If you threw a decent AGP card in there like a 1950Pro it would be a relatively decent cheap gaming rig.
 
Thanks for clearing everything up Albuquerque.:smile:

Ok now for an update. I installed the two PC3200 DDR400 DIMMs but it still didn't allow overclocing the P4 2.6GHz 800FSB any higher than my previous attempt at 1.69Ghz, HOWEVER, with this faster memory I was able to overclock the newly installed 2.4GHz 533FSB to 2.88GHz.:eek: The new cpu has a 18X clock so I ran the memory at 160MHz and the PCI bus at 40MHz. One problem though, at 2.88GHz the onboard AC97 audio didn't work..it's not even recognized. To fix this I lowered the speed to 2.6GHz and everything is now working. One minor performance issue though is that this 2.4GHz 533FSB P4 doesn't support hyperthreading like the 2.6GHz 800FSB model. :mad:

All in all not bad for a $60 upgrade..from 256MB DDR266 to 1GB DDR400 and from P4/Celeron 1.7GHz 400FSB to P4 2.6GHz 577FSB.
 
Last edited by a moderator:
i wonder how good hyperthreading is
benchmarks were done ages ago, but back then ther wasnt much that used it
 
You must log in or register to reply here.

Similar threads

S
Memory bandwidth vs memory amount *spin off*
2 3
Replies
42
Views
34K
Kb-Smoker
K
K
Real cores vs HT in future engines
Replies
18
Views
6K
trinibwoy
T
P
DDR266 and 400MHz FSB compatibility???
Replies
6
Views
1K
PC-Engine
P
S
Observations, thoughts and questions about X360 and PS3
2 3 4
Replies
64
Views
10K
overclocked
O
U
  • Locked
Overclocking Guide
Replies
1
Views
7K
Reverend
R
Back
Top