SGI: Hardware

Just out of curiosity, what controls the multipliers on these cpu's ? My HP uses the same cpu but the momboard only has DIP settings for up to 550 mhz. Is the cpu smart enough to run at twice 500 all by itself, say ?

This is a confusing one, I've just put a 1.4GHz Tualatin into a friends Mobo that only had support for up to 550MHz using the DIP switches. Had to update the BIOS for the machine to boot and the chip to be recognised, but it works just fine. The chips are multiplier locked on the CPU itself somehow and then the BIOS has to be able to detect the right CPU.

Which begs the question, what the hell are DIP switches for in the first place??

One guess is that these machines were made before Intel started locking the multiplier ratios on their chips.

Sound reasonable??

Kinda what I was wondering ... you *know* I had to try to kick them 500's up to 550 with the DIP switches, but it didn't do anything



must be .... I was pretty sure you couldn't run a slower chip faster because of that but not sure if a faster chip would still kick up to speed. Expected a heads-I-win, tails-you-lose thing from Intel .... I should try something a little quicker in here. Maybe someone who upgrades from 700 or so would like to amortize part off his gig-cpu purchase. Thanks for the encouragement, ruckus.

Old HP's might be a place to look for upgrade P-III's, too. This one is an Lpr and it uses the 100 mhz fsb in dually mode. It's been an okay box, for an Intel. It's not a Wintel tho

I have a HP netserver LC II, which used to have a Pentium 2 266. I found a 100MHz fsb P2 450 in a dumpster (just the card), so I put the P2 450 in the housing of the P2 266, put on the heatsink, put it in, calculated what the dip switches should be set for a fsb multiplier to go from 66MHz to 450, and I set it like that, and the P2 450, booted running @ 266MHz because it has a fixed multiplier. I guess I'll go back to the 266, and see if I can OC it with the dip switches.

IIRC the dip switches are only effective for Pentium II CPUs, starting from Pentium III in a 320 MoBo, the only thing you need to have to run fine in higher dual configs is a 8.2 / 8.3 or even 8.4 VRM.

You think that's what kicks the faster cpu's into higher rpms ? They check the voltage ?

makes sense ....

All,

It's legit - a company called Legasys did make SGI peripherals - and painted the casings in psuedo-SGI colours. I've seen bluish Octane 2 DAT drives and various CDROM incarnations.

Regards,

Ian

See also:
http://www.schrotthal.de/sgi/indigo2/index.html