[weblacky]

I wish. Everyone that came forward to comment had no examples of changing the fuel’s CPU speed. There was some agreement that it was likely the custom syntax of the flash command that mentions things like cpu frequency. But no examples.

No dealer I have contacted was able to find the info as well. Unless someone comes forward with old notes, it appears totally lost.

Given Fuels are mostly parts these days. It’s bad, bad news as we need to marrying different board with CPU modules now more than ever.

I was really hoping someone would know.

[chulofiasco]

I wish.  Everyone that came forward to comment had no examples of changing the fuel’s CPU speed.  There was some agreement that it was likely the custom syntax of the flash command that mentions things like cpu frequency.  But no examples. 

No dealer I have contacted was able to find the info as well.  Unless someone comes forward with old notes, it appears totally lost. 

Given Fuels are mostly parts these days.  It’s bad, bad news as we need to marrying different board with CPU modules now more than ever.

I was really hoping someone would know.

I'm actually in the middle of trying to build a fuel from parts.. lol

I can't believe that no one knows...

[jwhat]

I wish.  Everyone that came forward to comment had no examples of changing the fuel’s CPU speed.  There was some agreement that it was likely the custom syntax of the flash command that mentions things like cpu frequency.  But no examples. 

No dealer I have contacted was able to find the info as well.  Unless someone comes forward with old notes, it appears totally lost. 

Given Fuels are mostly parts these days.  It’s bad, bad news as we need to marrying different board with CPU modules now more than ever.

I was really hoping someone would know.

I'm actually in the middle of trying to build a fuel from parts.. lol

I can't believe that no one knows...

Hi weblacky & chulofiasco,

I have all the things required to test this except a faster Fuel CPU ;-) .

Looking for something faster than 600Mhz to test with.

Hamei indicated that you need to use the "flash" command.

If you do "flash -h" you will see that there is undocumented option: "-r nn set PrcReqMax" .

This may or may not be the "secret thing"...

But need to verify.

I also had email conversation with Ian Mapleson about this and he was a bit vague, no doubt as all this was a long long time ago, but seemed to indicate that the "flash" command was involved, as well.

Cheers from Oz,


jwhat/John.

[weblacky]

Ian was the "dealer" I talked to....he was vague because he also had not thought to write down the info, we all thought we could go to Nekochan forever.

Also you don't really need a faster CPU if you have 600Mhz CPU...you could downclock to 500Mhz, which a 600 Mhz will run, then upgrade back to 600Mhz...that would prove enough things to me.

[indy99]

Sorry, but I reread this thread, twice. No example is given. Mystery commands, parameters for hub, cpu speed, etc - still unexplained. Nothing actionable.

Can you provide any additional information that makes what’s hinted here actionable? Otherwise, I’m missing how we’re any further along?

Since you seem so appreciative of the advice already given, let me see if I can add any more. (-;

But first let me offer a cautionary disclaimer. I haven't had the opportunity to change cpu speed in an IRIX system in at least 10 years. As you've already discovered the exact process was never officially documented, almost certainly because SGI expected that operation to be preformed by a field engineer. So what I'm offering are not so recent recollections of having done it perhaps four or five times.... a decade or so ago.

Somewhere in the couple thousand or so posts I made on nekochan was one where I documented the procedure of flashing a Fuel from 500 to 600MHz. Just spent about three hours in the nekonomicon trying to turn it up without success, hoping to offer something a little more topical than my memory. Anyway, onto the business at hand.

Earlier in this thread I mentioned using "flash -f". My *recollection* is you'll be prompted to supply the cpu speed, hub speed and cache size. All three of those values can be obtained from an "hinv -vm", the cpu speed and cache size in the first few lines, the hub speed later just after the PCI adapter info. As an example, here's a few snippets from a Fuel hinv:

Code:

1 900 MHZ IP35 Processor.........
Processor revision: 3.0. Scache: Size 8 MB .........
HUB in Module 001c01/Slot 0: Revision 2 Speed 200.00 Mhz (enabled)

If you're buying a CPU on-line ask for an accompanying hinv -vm so you have the correct speed, hub and cache values. If they can't or won't provide that info, googling the PIMM part number might turn up an hinv with the info needed (I found searching the "hinv" sub-forum on nekochan by part number to be a very valuable resource. Especially when attempting to determine exactly what it was being offered by some unfortunately clueless ebay seller. A dedicated place to post hinv data here could prove equally valuable to the members of this forum.)

Since there isn't any readily available documentation, official or otherwise, were at the juncture where somebody's gonna have to suck it up any play crash test dummy. Normally this would have been the point on nekochan where I'd fire up a Fuel, run flash -f, capture the session output, and post the results here. Unfortunately my last Fuel has left the building.

If there aren't any other willing crash test volunteers, perhaps my post will jog loose some corresponding (or corrective) memories in somebody else with previous experience.

[jwhat]

Hi Indy99,

thanks that is sufficient info to test against.

I have a Fuel 600MHz and so can test by down grading it to 500MHz.

If there are no other special flash flags than the -f flag then I should be able to test this pretty easily...

Now you provide the pointer the "man flash" response make sense:

Code:

-f          Specify different (than currently in PROM) configurations
                  values to be used when the new images are flashed.  These
                  values include the speed of the CPU, hub, and size of the
                  cache.  This option should be used with great care as cause
                  the machine to freeze and be rendered unusable if incorrect
                  values are given.

Cheers from Oz,

jwhat/John.

[jwhat]

Hi Indy,

and some example hinv's:

500
CPU 0 at Module 001c01/Slot 0/Slice A: 500 Mhz MIPS R14000 Processor Chip (enabled)
Processor revision: 2.3. Scache: Size 2 MB Speed 250 Mhz  Tap 0xa
HUB in Module 001c01/Slot 0: Revision 2 Speed 200.00 Mhz (enabled)

600
CPU 0 at Module 001c01/Slot 0/Slice A: 600 Mhz MIPS R14000 Processor Chip (enabled)
Processor revision: 2.4. Scache: Size 4 MB Speed 300 Mhz  Tap 0xa
HUB in Module 001c01/Slot 0: Revision 2 Speed 200.00 Mhz (enabled)

700
CPU 0 at Module 001c01/Slot 0/Slice A: 700 Mhz MIPS R16000 Processor Chip (enabled)
Processor revision: 2.2. Scache: Size 4 MB Speed 350 Mhz  Tap 0xc
HUB in Module 001c01/Slot 0: Revision 2 Speed 200.00 Mhz (enabled)

800
CPU 0 at Module 001c01/Slot 0/Slice A: 800 Mhz MIPS R16000 Processor Chip (enabled)
Processor revision: 2.2. Scache: Size 4 MB Speed 400 Mhz  Tap 0xa
HUB in Module 001c01/Slot 0: Revision 2 Speed 200.00 Mhz (enabled)

900
CPU 0 at Module 001c01/Slot 0/Slice A: 900 Mhz MIPS R16000 Processor Chip (enabled)
Processor revision: 3.0. Scache: Size 8 MB Speed 450 Mhz  Tap 0xb
HUB in Module 001c01/Slot 0: Revision 2 Speed 200.00 Mhz (enabled)

I cannot find a 500MHZ hinv

EDIT: added 500 and HUB speeds, part no# are on "SGI Depot" fuel parts page.

All these have CPU = 2 x Cache Speed.


Cheers from Oz,


jwhat

[weblacky]

Is there anyway you can tie these to SGI PIMM part Numbers? That would allow people to reference what should be accurate specs when purchasing a CPU.

[indy99]

In the case of IP35 generation hardware, an L1 serial all post could provide part number details.

Including serial all data with an appropriate hinv -vm was the expected norm in our now defunct predecessor. I'll renew my suggestion that this forum consider a dedicated place for that data here.

[indy99]

Hi Indy99,

thanks that is sufficient info to test against.

I have a Fuel 600MHz and so can test by down grading it to 500MHz.

If there are no special flash other then the -f flag then I should be able to test this pretty easily...

Now you provide the pointer the man flash response make sense:
Cheers from Oz,

jwhat/John.

Hello John, don't believe we've 'spoke' since the nekochan days. Nice to hear from you again.

If possible I'd suggest doing a dry run first, without changing any values. Capturing that info should provide enough data to document the expected syntax with a lowered amount of risk exposure on your part.

Thanks for your valuable participation in this thread!