Low voltage processor in T60

[TravisD]

I can only find a couple references to this in the archives here. Everybody talks about upgrading to a T7200, T7400, or T7600, but what about, say, an L 2500, L7400 or similar. Either it becomes the last post of the thread or somebody says they never heard of anyone doing that. As long as it is socket M, no more than 667MHz FSB, and B2 stepping it should work, and give a significant boost to my battery life, right? I'm more concerned about that than eeking out small performance gains.

P.S., anyone want to sell a chip like that for cheap so I can test it out? I want to see if it will work and find out just how much juice the T60 will draw with a LXXXX CPU.

[kamaleon]

aren't those chips soldered directly to the mobo though?

[TravisD]

In my limited research I've only seen references to FCBGA T2xxx's, but I remember seeing a random post in a thread here on upgrading to a T7xxx where an X60(s?) owner said s/he replaced their L2400 with one, so I don't know. I thought that series all had soldered CPU's. I'm pretty sure some of the L7xxx's at least came as FCPGA. Someone please correct me if I'm wrong. I'm going to look into it more myself, and make sure I wasn't seeing converted chips. I wouldn't trust those.

[Binh]

Just undervolt (very easy) your current regular CPU and you get a ULV CPU. The advantage is that you still can get a high performance when you need.

[kamaleon]

What's the highest voltage for those low voltage chips? My T7200 merom has been running stable at 0.95v at full speed under some stress testing, although I didn't test it for long.

[Binh]

What's the highest voltage for those low voltage chips? My T7200 merom has been running stable at 0.95v at full speed under some stress testing, although I didn't test it for long.

U7600 (1.2Ghz): 0.8-0.975V, L7400 (1.5Ghz): 0.9-1.2V according to Wikipedia.

In my opinion, all LV and ULV processor are almost useless, except for their small form factor and a bit lower minimum voltage (for Pentium M it isn't advantage, though)

[kamaleon]

judging from those specs, i'd say the same... unless you're running your U7600 always at the lowest clock, 0.8v is pretty sweet

[mrybczyn]

I've researched this and given up. Apparently the ULV's won't work, even if you find socket-compatible ones.

So I just undervolt and underclock, it does okay. The main power draw tends to be the GPU anyhow, at least on my 60p.

Oh well, I bought this thing for the IPS screen, and the screen does rock. I wouldn't use it for road-warrioring, I'd use one of the 11.6 ULV's out these days.

Cheers,
Mitch

[TravisD]

I guess this may be moot now, as I found the following pages:
http://www.chiplist.com/ChipList2/tree3 ... e-SL9JU--/
http://www.chiplist.com/ChipList2/tree3 ... e-SL9SM--/
According to that, there were only BGA versions of those series.

From http://ark.intel.com, VID Voltage Range for:
All T2xxx with 667 FSB: 1.1625V - 1.30V
L2xxx:0.7625-1.2125V
T7200:1.0375V-1.300V
T7400:1.1625V-1.300V
T7600:1.0375V-1.300V
L7200: 0.9V-1.1V
L7400: 0.9V-1.1V

I got my first laptop ever (well, I had a hand-me-down POS as a kid), a T60 2007-66u last week, so I am new to this, but I have been reading up on under-volting. I will definitely try that out. I had actually wondered if those LV chips are just factory under-clocked and under-volted T series, and I could get close to it with a little luck on a good Tseries chip.

[TravisD]

I've researched this and given up. Apparently the ULV's won't work, even if you find socket-compatible ones.

So I just undervolt and underclock, it does okay. The main power draw tends to be the GPU anyhow, at least on my 60p.

Oh well, I bought this thing for the IPS screen, and the screen does rock. I wouldn't use it for road-warrioring, I'd use one of the 11.6 ULV's out these days.

Cheers,
Mitch

Thanks for sharing your findings. I think you were one of the posters I was referring to in the OP. I'm just trying to find ways to reduce power draw without dimming my screen more than a notch or maybetwo and having the nine cell battery hanging out the back. This is my only portable rig. I debated hard on whether to get this $350 refurb T60 or some cheapo feeling thing with stellar battery life. I made the right choice, I just need to tweak a bit to make it through a day of classes with a little etc. thrown in. I also ended up getting a bay battery off the Lenovo Outlet for $40 (open box). I hope it's not really as crap as I've read.

[kamaleon]

From http://ark.intel.com, VID Voltage Range for:
(...)
T7200:1.0375V-1.300V

I don't know what's up with those specs but my T7200 idles at 0.95v, factory setting

[TravisD]

I don't know what's up with those specs but my T7200 idles at 0.95v, factory setting

Yeah, now I'm not sure what those are supposed to mean. I have been playing with RMclock and the stock ranges for my T2500 seem to be 0.95 (6X) to 1.25 (12X).

12x can run at 1.0125, 11x can go down to...I think it was 0.975 (i would have to look it up), 10x ran all night at 0.95, and that's as low as I am allowed to set it. If I knew it could do the same at 0.9375 I'd set it at 0.95. I'm thinking a VID pin mod to go lower sounds like fun.

This is more than a little annoying. I bet 6x could do 0.8, maybe lower.

[kamaleon]

My 7200 runs fine at 0.975v at x12... I've tried making Prime95 tests and I get errors straight away, but at "normal" usage I haven't seen any BSODs or anything at all so I'm running it like that

[TravisD]

Those voltages are what's stable for at least a round (8K -64K) of Orthos on mine. It seems to either fail in the first couple minutes or run all night.

[kamaleon]

actually, i meant 0.95v, if that changes anything... my bad.