Undervolted P4-M vs Speedstep P4 vs Speedstep P-M vs AMD CnQ

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sn1009
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Undervolted P4-M vs Speedstep P4 vs Speedstep P-M vs AMD CnQ

Post by sn1009 » Sun Jun 19, 2005 3:23 am

As far as I understand the P4-M does not support Speedstep (because its multiplier is locked).
I have read that a "normal" desktop P4 along with a P-M and an AMD CnQ chip does.

I need the less power consumpting CPU setup for my HTPC so will I be better off using an undervolted P4-M, a Speedstepped P4, a Speedstepped P-M or a AMD CnQ.

I have done some searching on this topic but have not been able to find some power consumption comparisons between the different solutions.

If this topic has been discussed I would be happy with a link..

thx
~sn1009

jojo4u
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Re: Undervolted P4-M vs Speedstep P4 vs Speedstep P-M vs AMD

Post by jojo4u » Sun Jun 19, 2005 5:42 am

You don't need special undervolting power figures. The rule of thumb is: the lower the frequency and voltage, the lower the figures.

P4: have a look at http://forums.silentpcreview.com/viewtopic.php?t=20906. Conclusion: 2,[email protected]
P4M: have a look at http://will.dashwood.me.uk/pentium4m-2.htm
You need some FSB-changing tool. The voltage stays the same, though. For a tool, have a look at http://forums.silentpcreview.com/viewtopic.php?t=20872. Conclusion: 1,2Ghz@default vcore
Athlon 64: All Athlon 64 (and all Semprons >=1,8Ghz) support Cool'n'Quiet. Get the 90nm parts. Conclusion: 800Mhz@1,1V
P-M: There is support for EIST which equals performance-wise to Cool'n'Quiet.
AOpen i855GMEm-LFS and DFI 855GME-MGF: Unstable support of EIST (http://www.silentpcreview.com/article218-page9.html)
AOpen EY855-II: at least manual ChrystalCPUID support (http://www.silentpcreview.com/article236-page6.html)
Aopen i915GMm-HFS: the german magazine C't claims that RmClock is unstable with the included Aopen fan speed tool. Which indicates that it is stable without the tool.

Overall Conclusion: P4 and P4M don't have very good sulutions. P-M EIST support seems to be quite rare.
P-M platforms are quite expensive, too. Further research would be necessary. The Athlon 64/Sempron provide a quite mature solution. But don't get a nForce 4 chipset.
With working EIST/Cool'n'Quiet a P-M and a Athlon 64 will need equal power at idle. The P-M platform should draw less power since it is optimized for the lower load power.
Last edited by jojo4u on Sun Jun 19, 2005 8:50 am, edited 1 time in total.

sn1009
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Re: Undervolted P4-M vs Speedstep P4 vs Speedstep P-M vs AMD

Post by sn1009 » Sun Jun 19, 2005 6:08 am

Thanks for your info..
jojo4u wrote:The Athlon 64/Sempron provide a quite mature solution. But don't get a nForce 4 chipset.
Why don't you recommend the nForce 4 chipset. As far as I'm aware alot use this chipset for HTPC's as it features dolby digital hardware encoding..
jojo4u wrote:With working EIST/Cool'n'Quiet a P-M and a Athlon 64 will need equal power at idle. The P-M platform should draw less power since it is optimized for the lower load power.
Athlon 64 is definately the way to go for HTPC use then.
I'm off to do some more research about these Athlons as my last two builds have been Intel so I'm not quite up to date on the AMD front
:(

jojo4u
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Post by jojo4u » Sun Jun 19, 2005 8:04 am

Regarding the nforce 4: Read through this thread and decide by yourself. An actively cooled chipset is a big no-no for me.

sn1009
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Post by sn1009 » Sun Jun 19, 2005 8:22 am

jojo4u wrote:Read through this thread and decide by yourself.
I'll look into that..thx for pointing me in the right direction..

~sn1009

mb2
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Post by mb2 » Sun Jun 19, 2005 8:40 am

just a little clarification on the P4-m (link doesn't work btw).. the multiplier will be locked at 12x, which means 1.2ghz at the default fsb (400) .. with an 800fsb board u can get 2.4ghz with no problem however, and the better ones will max out the fsb of whatever board, so i think u can get like 3.2ghz if u really want to (not good for silence thou)
however, the P4-m based Celerons are locked at their normal multiplier (cuz they never had any speedstep).. and they have 256kb cache, which is the same as the earlier p4s, better than the desktop celerons of the time..
surely it is possible to change the voltage of these with boards which allow it in the bios? 1.2ghz certainly wouldn't need default voltage..
i think P4-M is a very good solution, cheaper than the others..

i would say a P-M would be the ultimate.. even if p-states dont work fully with any board, i would have thought u can lower FSB, and they aren't that hot to begin with.. slower P-Ms and Celeron Ms can be very decent value.

A-64/s754 sempron is also nice; having the advantage of boards with CNQ working, and cheaper than P-M solution.. the 90nm ones are nice and cool anyway.. but i would think getting NF4 would defeat the point of getting such a cool cpu, atleast somewhat.. especially when u consider when the system is idle- the board will actually be making more heat than the CPU as there isn't much power management for the chipsets afaik..

if u dont care about how noisy it is when ur using it (more intensively) then perhaps that gives the upper hand to the A64/semp route over the P-m?

sn1009
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Post by sn1009 » Sun Jun 19, 2005 9:43 am

mb2 wrote:i think P4-M is a very good solution, cheaper than the others..
Well.. I will most likely be getting a second hand Athlon 64 and mobo if I decide to go that route...
mb2 wrote: especially when u consider when the system is idle- the board will actually be making more heat than the CPU as there isn't much power management for the chipsets afaik..

if u dont care about how noisy it is when ur using it (more intensively) then perhaps that gives the upper hand to the A64/semp route over the P-m?
I do care about that.. I will most likely be timeshifting on my sat-card which does not have hardware decoding so the CPU will be busy...

The nforce4 chipset is not a must for me as the channels I receive does not offer dolby digital anyway (most of them anyway)..
I will be getting a envy24 based soundcard (most likely the audiotrak prodigy 7.1) so I don't know if that could "replace" the encoding that the nforce4 is known for if I decide not to get a nforce4 based mobo..

~sn1009

hmsrolst
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Re: Undervolted P4-M vs Speedstep P4 vs Speedstep P-M vs AMD

Post by hmsrolst » Sun Jun 19, 2005 10:09 am

jojo4u wrote:P-M EIST support seems to be quite rare.
P-M platforms are quite expensive, too.
I have quite a bit of experience now with P-M's using an ASUS CT-479 adapter on a P4P800 (SE. VM and Deluxe). EIST works without problems on all of them. I've used 2 725's (1.6 GHz) and 1 735 (1.7 GHz), and all have run with a 33% overclock while undervolted using EIST.

This is a pretty reasonable solution, especially since Dothan's are not that expensive when purchased on ebay--you can currently pick up a 1.7 chip for $140 plus shipping using Buy-it-Now, and rumors are that Intel will be lowering prices by the end of the month. You can also find some reasonable deals on used P4P800 SE's on ebay too, so the mobo, CPU and adapter can come in less than $300.

If you're interested in P-M, I can provide more info.

jojo4u
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Re: Undervolted P4-M vs Speedstep P4 vs Speedstep P-M vs AMD

Post by jojo4u » Sun Jun 19, 2005 11:13 am

hmsrolst wrote: I have quite a bit of experience now with P-M's using an ASUS CT-479 adapter on a P4P800 (SE. VM and Deluxe). EIST works without problems on all of them. I've used 2 725's (1.6 GHz) and 1 735 (1.7 GHz), and all have run with a 33% overclock while undervolted using EIST.
Yes, you are right. I had the CT-479 in my mind, but it didn't seem to be a very "clean" solution. It's not on the cutting edge, but not as expensive as the native boards. And the HSF was an issue, too.
After going through this post at xtremesystems.com last posts, I learnt that you can use a Zalman 7000/7700 and that EIST is working (on some boards). Btw, EIST is short for Enhanced Intel SpeedStep. Cpuid.com offers an utility calles EIST. We should refer to it as EIST utility in order to keep things clear.

Under the light of the working EIST, I would check wether the "old" platform by Asus offers everything I need and go with it.
The power under full load should be a good deal lower compared to an Athlon 64. Have a look at this GamePC article: http://www.gamepc.com/labs/view_content ... uso&page=3

hmsrolst
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Post by hmsrolst » Sun Jun 19, 2005 12:13 pm

BTW, just to clarify, I have only used EIST to change the multiplier or voltage statically, not dynamically. I don't know if it will work like CPUID to respond to load.

sn1009
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Re: Undervolted P4-M vs Speedstep P4 vs Speedstep P-M vs AMD

Post by sn1009 » Mon Jun 20, 2005 7:25 am

jojo4u wrote: Under the light of the working EIST, I would check wether the "old" platform by Asus offers everything I need and go with it.
The power under full load should be a good deal lower compared to an Athlon 64. Have a look at this GamePC article: http://www.gamepc.com/labs/view_content ... uso&page=3
I think the P-M solution is a bit out of my price league... also the review does not include the Athlon64 at its lowest 800MHz setting so I would presume that the power consumption would be somewhat lower at this setting.

If the reason for leaving out the 800MHz setting is based on the fact that Dothan is not able to clock down to 800MHz and is therefore not comparable with the Athlon64 at this point is something that I am not aware of...

~sn1009

mb2
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Post by mb2 » Wed Jun 22, 2005 4:56 pm

p-m isn't always expensive.. 1.5, 1.6ghz p-m isn't too bad IIRC, and 1.5ghz celeron M is like the same price as a 2600+ sempron.. if u get 90nm then these can OC to high hell anyway without being so hot. (cooler than A64??)

if the P-M were to underclock it would go to 600mhz rather than 800 anyway.

sn1009
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Post by sn1009 » Fri Jun 24, 2005 6:19 am

mb2 wrote: if the P-M were to underclock it would go to 600mhz rather than 800 anyway.
Well... I was refering to the A64 when pointing out that the review didn't test at these speeds. The old version of A64 clocks down to 800MHz when idling.
As far as I understand the P-M offers dynamically underclocking and undervolting so it would be your choice if you want the P-M to clock down to 800MHz or 600MHz when it's idling.

~sn1009

Ozy666
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Post by Ozy666 » Fri Jun 24, 2005 8:56 am

Just to clear up a little misinformation...

The nforce4 does NOT do Dolby Digital encoding. The chipset that does this is the nforce2 with SoundStorm.

Dolby Digital encoding means taking multichannel non-Dolby audio (games, etc...) and turning it into a DD stream that you can send to a receiver with DD decoding. The advantage is using a single digital audio connection instead of 6 wires for multichannel audio.

This has no effect on Dolby Digital passthrough from DVDs and HiDef streams, which most motherboards can do anyways.

There are, AFAIK, two cards that implement this Dolby Digital encoding, the XMystique, and a new Turtle Beach card.

The nforce4 is hot, and is usually actively cooled, but there there is a Gigabyte motherboard that does passive cooling and new Abit and Asus boards that do passive cooling with heatpipes. Others have replaced the active cooling on MBs, and I plan on doing the same with a DFI Lanparty Ultra-D.

Ozy

sn1009
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Post by sn1009 » Sat Jun 25, 2005 1:56 am

Ozy666 wrote:Just to clear up a little misinformation...

The nforce4 does NOT do Dolby Digital encoding. The chipset that does this is the nforce2 with SoundStorm.
My bad...
Ozy666 wrote: The nforce4 is hot, and is usually actively cooled, but there there is a Gigabyte motherboard that does passive cooling and new Abit and Asus boards that do passive cooling with heatpipes.
Ozy
I'm looking for a mobo for my HTPC to go along with a 90nm socket 939 winchester or venice (harder to get second hand though)..
For HTPC am I better off getting a Nforce4 chipset rather than a VIA..or something else..
I would think that the possible performance increase using the Nforce4 chipset is not as valuable as the additional heat added to the system..

~sn1009

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