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Fuel R14k cpu into octane1 ?

Posted: Mon Nov 06, 2017 5:31 am
by ssch1034
Dear All,
is it possible to put a R14000/600Mhz (from a Fuel PIMM) onto a Standard R12000/300MHz socket on a single CPU Octane board?

Q1. Is the CPU hardware/pin layout compatible?

Q2. Would it work but remain at 300MHz?

Q3. Can the CPU frequency by jumper'd to another frequency?

Thanks.

Regards
Stefan

Re: Fuel R14k cpu into octane1 ?

Posted: Mon Nov 06, 2017 9:14 am
by mazzinia
pending other more knowledgeable inputs, but I think the module connectors are different

Re: Fuel R14k cpu into octane1 ?

Posted: Mon Nov 06, 2017 9:39 am
by Irinikus
The answer is unfortunately no, as they make use of two completely different connection interfaces:

Connector on Octane CPU module:

uuw6u2uk.jpg


Connector on Fuel CPU module:

s-l1600-40.jpg

Re: Fuel R14k cpu into octane1 ?

Posted: Mon Nov 06, 2017 11:40 am
by Raion-Fox
You cannot even remove the CPU from one module and put it on the other without insanely specialized equipment. It's not worth it.

Re: Fuel R14k cpu into octane1 ?

Posted: Mon Nov 06, 2017 9:56 pm
by japes
This was covered not long ago: viewtopic.php?f=3&t=16731958

TL;DR: R14000 has more pins and runs a lower voltage than the R12000 - CPU swap is not possible.

Re: Fuel R14k cpu into octane1 ?

Posted: Tue Nov 07, 2017 2:01 am
by jwhat
Hi ssch1034,

when it comes to old SGI gear and Nekochaner's sometimes it is just to see if it can be done that provides motivation rather than rational reason.

But this one falls into the way to hard basket.

I think one of the complications of MIPS architecture is the caching implementation, which is critical to getting good performance out of chip (keeping super-scaler instruction pipeline filled), suspect that a lot of this is managed via the complex daughter boards that each of the various OS, Octane, Origin ... variations have around them.

Like lots of other retro-computing work, the reverse engineering required to replicate this, requires serious equipment and deep digital electronics/engineering expertise.

Some of the work done by the retro Macintosh & Amiga communities is fantastic, if completely irrational ;-)

If you want to great retro-project suggest making a much larger memory V12 or 8GE IR board ;-)

Cheers,

jwhat

Re: Fuel R14k cpu into octane1 ?

Posted: Tue Nov 07, 2017 6:15 am
by ssch1034
Dear All,

thank you for the answers. The number of pins/contacts and voltage was the information I didn't find online,
so thank you all for the input. Recently a R12k-360MHz sold for almost nothing. I guess that would have been
an option to increase the speed - or at least clock speed - potentially by 20%. I'll try again once I found and
actually get a faster R12k chip.

Kind regards
Stefan

Re: Fuel R14k cpu into octane1 ?

Posted: Tue Nov 07, 2017 6:33 am
by Irinikus
jwhat wrote:If you want to great retro-project suggest making a much larger memory V12 or 8GE IR board ;-)


I’ve always wondered why they never released an 8GE IR board, as there is space for an extra 4 GE’s on the boards that they released.

Re: Fuel R14k cpu into octane1 ?

Posted: Tue Nov 07, 2017 12:00 pm
by japes
ssch1034 wrote:Dear All,

thank you for the answers. The number of pins/contacts and voltage was the information I didn't find online,
so thank you all for the input. Recently a R12k-360MHz sold for almost nothing. I guess that would have been
an option to increase the speed - or at least clock speed - potentially by 20%. I'll try again once I found and
actually get a faster R12k chip.

Kind regards
Stefan


I think it was mentioned in the topic I linked, but unfortunately some of the faster modules went with BGA parts instead of LGA. Pretty expensive to move those chips around successfully, it was mentioned you'd want to expect some failure, at that point you might as well wait for the CPU module you want. I can't remember if it was covered, but it was mentioned taking some of the slower chips off octanes and putting faster ones in...I think. You'll need to search these forums. I would maybe look for a 400 MHz PIMM from an Origin 2000. I think those are LGA and you might be able to place them on a 300 MHz Octane board, if it's LGA and not BGA. OKAY, didn't read, but here's a topic you should check out (LONG): viewtopic.php?f=3&t=1230

I guess my question would be what do you want to do with the Octane? Especially if you have a Fuel around. My dual-600 Octane2 is slower at pulling data from disk and serving it up to NFS clients than my dual-600 Origin 350 by quite a bit. If just for general clicking around I'd put any dual CPU in an Octane, like dual 195 or 270 for example. It really transforms the interactive capability. Single 400s should be easy to find if you need faster single thread performance, they seem to have been popular in the Octane2. If you just want speed I'd look at Fuel/Tezro/Orgin350/Onyx350 machines.