R51 processor question

[Nohbody]

This is purely for the sake of sh*ts and grins, without concerns for anything like the practicality of the thing.

If I were to want to up-gun the processor for the laptop mentioned in my sig, would any of the Pentium M line work, only certain models of CPU, or would this hypothetical me be out of luck entirely?

The idea came to me while strolling through the HMM earlier today, out of boredom, and being something of a DIY type with desktop PCs the idea of upgrading some parts or others is a familiar thought.

[sarbin]

should be able to use any of the 7x5 dothans.
see: http://www.thinkwiki.org/wiki/Intel_Pen ... 8Dothan%29

[Harryc]

I have quite a bit of experience with R51's and the best bang for the buck processor upgrade is the 1.8Ghz Pentium M. The issue with the R51 is that the fan/heatsink is not tremendously efficient at handling higher temps, so if you put in a 2.0Ghz CPU or higher things get toasty.

[jronald]

I put a 1.7 in my wife's and was totally unimpressed.
I did not expect to see any improvement, and I think it was less. I really did not expect significant extra heat, and had tons of it.
For the heat issue alone, I removed it and went back to the 1.6.

Ron

[Nohbody]

I didn't think there'd really be that much of an improvement with upgunning only the CPU, at least not at a bang/buck ratio that I would find appealing. With a quick glance at eBay, earlier, going up beyond 745 that ratio takes a serious nosedive on a laptop for which I've already spent significantly more than I intended when I first started out.

(and for the record, mine's a 1.5; not sure about the specific CPU without opening up the case, which is really too much effort for a hypothetical scenario )

[RealBlackStuff]

Download and run this CPU-Z program to get the CPU details: http://www.cpuid.com/

[Nohbody]

I knew about CPU-Z, just didn't remember it, since it's been ages since I've concerned myself with benchmarking and exact hardware configurations. Thanks for the reminder.

[edit]
And it says I have a 705 Banias, BTW. The only two entries on eBay for that model are 1.5 and 1.6, neither of which is worth the effort even if I did have a serious interest in the issue. $34 for 100MHz improvement is silly.

[jronald]

Your welcome to the 1.7 I have, $10.00 including USPS Priority.

Ron

[Nohbody]

$10 shipping included? Spiffy. PM OTW.

[jronald]

Specs are as follows

7412A460 SL6N5
RH80535 1700/1m

Let me know if it will work for you.

Thanks
Ron

[hiram]

I am thinking of doing something similar to Nohbody for my friend's R50 1829-6DM which has a 1.5GHz Banias. The idea being to replace it with a 745 1.8GHz Dothan that I can pick up cheap locally.
http://vic.gumtree.com.au/c-Stuff-for-S ... Z238644785

There have been some comments so far about increased heat doing this on a R51. Does anyone know if it is the same with the R50? Same/worse/better? Although I do not understand why there could be a heat issue, seeing as how faster Pentium Ms have the same or less wattage, according to the technical specs (for the same FSB of 400).

[jronald]

Geez, its possible I installed it wrong, but there is only so many ways to put the stupid thing in!
That said, I did not notice a whole bunch of improvement when it was installed.
The wife constantly complained about the heat.
I fixed it, I took it out!

Ron

[Nohbody]

Just a follow-up, for anyone who cares.

(*sound of crickets*)

The processor from jronald came in a few days ago, and is now up and running in my laptop (fortunately I had a tube of thermal paste already available, from a previous project, so there was no delay in schlepping out to Rat Shack or whatever to pick one up). I haven't noticed much of an improvement in speed, but I didn't think to benchmark things for before/after comparisons, and for $10 it's not like I'm going to be bankrupt for doing something 2% or whatever faster.

Now I have a 1.5 that I probably can't even give away...

[misfit]

Just a follow-up, for anyone who cares.

(*sound of crickets*)

The processor from jronald came in a few days ago, and is now up and running in my laptop (fortunately I had a tube of thermal paste already available, from a previous project, so there was no delay in schlepping out to Rat Shack or whatever to pick one up). I haven't noticed much of an improvement in speed, but I didn't think to benchmark things for before/after comparisons, and for $10 it's not like I'm going to be bankrupt for doing something 2% or whatever faster.

Now I have a 1.5 that I probably can't even give away...

I use Notebook Hardware Control (NHC) and as each 'new' ThinkPad comes my way I spend a day or more tweaking the vcore to it's lowest stable setting for each of the speed-steps (and testing thoroughly as, sometimes a frequency / vcore that's stable 'locked-in' will give trouble as it changes on the fly).

I've found that, with the higher-rated CPUs you can get way with far less vcore, especially with Dothans. My best Dothan/s that I still have the digits for are a 715 (1.5GHz) that will run at 0.972V at 1.5GHz all day rock-solid and a 725 (1.6) that only needs 1.004V at full speed. These things hardly, if ever run the fan up.

I'm annoyed that I don't still have the figures for a couple of faster 100MHz FSB Dothans that I used to have. I had a 755 (2GHz) that, while it required around 1.1V to run at 2GHz it would run all day at 1.8GHz with a vcore of (from memory) about 0.9250V! In fact I had to mess with the fan settings so that it would come on from time-to-time as the rest of the components got too hot with no fan running.

So, while a 755 (or 765) may run a bit too hot at stock in an R51 if you want to tweak it a bit, then throttle it to it's next-to-highest speed-step you'll get a big increase in power and, if anything, a decrease in heat. What's not to like? It's a shame that 745s, 755s and 765s are still fetching a few more bucks than I have to throw around.

Cheers,

[Nohbody]

The info is appreciated, but I have little ambition to put much more money into this laptop save perhaps a new battery at some point in the near future, as it only gets used on the relatively rare times that I'm out on the road.