DV4 & 5t Speed Steps ?

I bought a pretty basic DV4t for my daughter for Christmas. Did a fresh Vista 32 install and everything is working nicely as advertised. However, when I check through CPU-Z (v1.49) it only indicates a down clock to 1595Mhz. The Vista CPU meter gadget though shows one processor at or near 0 at idle with the second at about 28%. I also have a DV2700tv in the house, also with a fresh Vista install, and it down clocks to 800Mhz.

CTO Spec’s are:
DV4t, P7350, 4GB ram, 160GB HD, Webcam, 802.11n w/Bluetooth, Lightscribe,12 Cell, BIOS F.24 (factory).

Unlike AMD systems, my understanding is that there is no driver required like there is for AMD Cool-n Quiet and that the speed steps are initiated between the BIOS and the OS with the correct chip-set drivers installed. My thoughts are that either:

(1) There is a problem with the BIOS F.24
(2) There is a problem with CPU-Z and this config
(3) The is a problem with the processor
(4) Or the P7350 doesn’t down clock like the T8100 that is in the DV2700tv

I re-installed the chipset drivers just to make sure all was correct. Device manager is clear and no problems there. I checked Intel and the P7350 supports "Enhanced Speedsteps" and it at least is down clocking from 2Ghz to 1595Mhz. I’ve also searched the forums and no luck there either.

Any idea’s out there? Anyone have a similar issue with there DV4 or 5t?

Thanks.....

 

Bump..........

 

P7350 doesnt have Super Low Frequency Mode (SuperLFM) which cuts the FSB in half on idle.

266mhz FSB x 6 multiplier (idle) = 1595mhz

The T8100 has on the other hand has standard idle of

200mhz FSB x 6 = 1200mhz

Now with superlfm set to 8x idle

100mhz fsb x 8 multiplier = 800mhz.

My dv2500 is set to idle at 600mhz. (6x SuperLFM)

 

Sorry for the response delay, but I had to watch the Gators give the Sooners another lesson in SEC football ; )

At-any-rate….. Thanks very much for the time and the excellent answer. I vaguely remember reading something somewhere about the Santa Rosa platform and Super LFM but I guess it never registered. I sat here for a good while with the DV2700tv & DV4t side-by-side scratching my head trying to figure out why the T8100 would clock down to 800Mhz while the P7350 would only go down to 1595Mhz. Checked the BIOS, chipset drivers, Intel data sheet, CPU Z compatibility….. everything I could think of… OH well, at least my 4th possibility was on the right track.

Just wondering…. but where did you find the info for the P7350 and do you know if this applies to all “P” series 25watt chips? Also, I have to wonder if the reduced speed-steps are because it’s not required for the 25watt processors as opposed to the 35watt "T" series ? Seems to me 133Mhz x 8 @ 1064Mhz would still save some battery if the system were stable.

Thanks again and it’s very nice to know there are folks like you here willing to answer the tough (though obvious to you) questions!!

 

I suggest you read this article.

According to this. The 2nd gen Penryns (Montevina Platform) is supposed to have SuperLFM/Dynamic FSB Frequency switching. Im guessing CPU-z just isnt recognizing it.

 

How does it go… “When all else fails read the directions”? Well….. after you suggested it might be a problem with CPU-Z, I went back and looked at their web page again and read around a bit. Answer: With CPU-Z open, Press F9 to change the computational model. Direct Hit !!

T8100 no F9


P7350 no F9


P7350 with F9


While in this mode CPU Z no longer displays the multiplier but………..
798/133= 6. Therefore I’d say all is well and, as you discovered, the “P” series processors do in fact support Super LFM and cut the bus speed by half. I’m not sure why F9 is required for the P7350 or perhaps the entire “P” series. Never-the-less, it’s working using the alternate computational model (what ever that is). Thanks for the help and hopefully some other seriously OC individual will find this information useful.

 

CPU-z in the past has insufficient support for mobile cpu's. This is why i guessed it was cpu-z that was the issue.

Its great to know that it actually does have SLFM.

 

Do any other "P" series chips in current DV series notebooks display the same behavior? i.e. do you need the F9 selection in CPU-Z (v1.49) to display the full down clocked capability of the processor?

Just wondering?