A31 System Board 1.9 or 2.0 upgrade options

[Paul Pennington]

I'd like to upgrade my wife's A31 with a faster CPU, and would prefer a complete system board with CPU and proper fan rather than buying the parts separately. A bottom assembly or barebones unit would be OK too. It must be 1.9 or 2.0 GHz which according to the Hardware Maintenance Manual would be part number 26P8428 or 26P8429 for the system board (her unit has an XGA screen). These should be found in one of the following A31 models:

2652-P3x, P4x, P5x, P6x, PGx, PKx, PWx, PXx, PYx, PZx, PCU, PRF, PRU

2653-P8U, P9U, PBU, PEU, PGB, PGH, PHT, PPC, PQF, PQU

2654-P5x

Anyone have one available?

[b]Note from Admin:[/b] Moved at OP request for discussion of options.

[scosgt1]

You can go to 2.4 Ghz in an A31, and the install is a lot easier than changing an entire motherboard.

[underclocker]

FYI, I upgraded an A31 1.6GHz to 2.0GHz about a year ago.

I picked up the 2.0GHz CPU for $20 and the improved fan for another $20. I had some Arctic Silver thermal grease on hand.

This upgrade is far easier and faster than swapping a motherboard or even swapping an LCD to a differnt complete base.

The difference between the 1.6 and 2.0 was quite noticeable. I also noticed a significant differnece between 512MB and 1GB of RAM.

[scosgt1]

Just be careful removing and installing the CPU, I just managed to kill a motherboard (must have somehow disconnect the zif socket)

[Paul Pennington]

[quote="scosgt1"]You can go to 2.4 Ghz in an A31, and the install is a lot easier than changing an entire motherboard.[/quote]

The consensus I'm reading on the reports here and elsewhere is that there's a good reason IBM didn't put a CPU faster than 2.0 GHz in the A31: they get too darned hot!

[Paul Pennington]

[quote="underclocker"]FYI, I upgraded an A31 1.6GHz to 2.0GHz about a year ago...
[/quote]

I was under the impression that there were differences in the system boards -- I had to use two different BIOS upgrades for my 1.9 and my wife's 1.6 A31's.

Does anyone know for sure that the boards are the same and only the CPU and heat sink are different? I will admit the specs look the same to me.

[underclocker]

The different BIOS versions for the A31 models have always stood out to me as an unanswered question.

It seems that the most recent versions of A31's, whether "p" models or not, have the newer boards with the BIOS that starts with 1NET. All the model numbers that use this BIOS have the last three characters starting with Pxx, Qxx, Rxx or CTO.

The other obvious differences are that they were released later in the A31 product cycle, had at least 1.9GHz CPU's, and had the stronger fan (62P4092).

Perhaps an A31 expert can provide more clues about the board differences. All other spec.'s appear identical. Perhaps it was a manufacturing plant change or perhaps the boards are truly designed to better cope with more powerful CPU's?

In any event, many people have used both boards to upgrade to 2.0GHz and beyond. I am using one of the 1GET BIOS boards with a 2.0GHz CPU and the newer/stronger fan without any obvious issues.

(Perhaps this thread needs to be split between the Marketplace and the RAG fourm?)

[fasterbybike]

It's my understanding that the 1NET bios is used with mobos that have the IBM Secure Chip(TCPA). The 1GET bios is used with mobos without the IBM Secure Chip(TCPA).
There are also differences in the graphics chips and video RAM between various mobos.

[Paul Pennington]

I don't think the secure chip determines which BIOS is used: I have two A31's, both with secure chips, and they call for two different BIOS'es. The CPU speed factor seems to fit better: The "PQR" models (xxxx-Pxx, etc) seem to have either 1.9 or 2.0 GHz CPU's and take the 1NET... BIOS.

I guess the whole question is moot now: when I upgraded the BIOS on both machines last month, there was only one version for both. But I'm still curious as to why there was a difference before.

I didn't realize the 2.0 CPU prices had fallen so much -- I think I'll try a CPU and fan upgrade first and see how it goes.

Does anyone know of a good source for the fans?

[sausage888]

I have upgraded my two A31's which both came with 1.8Mhz CPU's with 2.4Mhz CPU's and in each case just re-installed the old fans. It is a fairly simple task (a whole lot easier than a motherboard). I have not had any heat issues requiring souped-up fans to handle it.

Periodically, I check with MobileMeter and it rarely goes above 48C (118F). I thought more like 90C(200F) was the danger point.