SGI: Hardware

I was wondering, as a hobbyist, i wanted to makes some minor upgrades(as in low-cost) on my Octane box. Like switching the SI board for an MXE+Trams (found some cheap) and i got a load of memory on its way (thanks el_mariachi)

But i was wondering about the processor... I found a dual R10k 250Mhz 1Mb cache for about 40$... is it worth replacing the single R12k 270Mhz 2mb cache? since im still kinda struggling with things as stupid as installing new packages. but i do know that i can push the cpu to its limits doing basic stuff like web surfing...

Oh and another thing, tough not hardware related. How does one configure GR_OSVIEW ? mine only shows the cpu column, nothing else.

gr_osview -a

regards

laurent

henrycault wrote: I found a dual R10k 250Mhz 1Mb cache for about 40$... is it worth replacing the single R12k 270Mhz 2mb cache?

That depends on what you're doing with it ... For web browsing, you want a single fast CPU, whereas, for example, rendering would be faster with dual slightly slower CPUs.
If you're able to find a cheap dual 300 with 2MB of L2 cache, it would provide a speedup in both tasks from your current configuration.

henrycault wrote: How does one configure GR_OSVIEW ? mine only shows the cpu column, nothing else.

See the man page, it has instructions on configuring a ~/.grosview file where you can specify which columns you want it to display.

yeah thanks, i did found gr_osview -a after looking at the man pages...

As for the processor, is there a difference in performance from lets say, a R10k, R12k, and R14k if they were all at the same speed? Or are they only newer versions that are capable of going faster?
Because i think R10k stops at 250Mhz, and R12k starts at 270Mhz and so on

MIPS is unusual in that it tends (in the SGI processor module implementations, anyway) to scale pretty linearly with clock speed (most CPUs slow down in effective work/MHz as the MHz increases). What you'll get is bigger Rx000 numbers as the MHz increases (since that was the big reason to rev the processors), and the performance goes up as the MHz increases. A bit rambling, so I guess I'll say it again:

As the clock speed of the processors increased, SGI/MIPS needed to revise the processors to allow them to function at that speed (shrink, tweaks to logic to fix timing problems, etc.) At the same time, SGI/MIPS tweaked other bits (cache interfaces, TLBs, branch prediction) to improve performance at the new speed, with the net result that a 400MHz Octane processor module is roughly twice as fast as a 200MHz processor module.

In short, look at the MHz ratings.

A 250 MHz PM20 is a good upgrade from a 175/195/225 and possibly even 250 MHz R10k, but for your machine I'd save and look for a 360-400MHz PM10 (single processor) or PM20. A dual but slightly slower processor module is probably not worth a $40 upgrade.

i would recommend any kind of r12k or higher since interactive use doesn't benefit much from smp.
looking at the prices these days it should not be a problem at all

As i though, MIPS revisions exists to support faster cpu speeds, so i think im gonna do as you told and go for faster clock speeds then. Might leave the dual-cpus alone unless a real bargain comes in. Thanks

henrycault wrote: As i though, MIPS revisions exists to support faster cpu speeds, so i think im gonna do as you told and go for faster clock speeds then. Might leave the dual-cpus alone unless a real bargain comes in.

Dual is really nice tho ... one other point : the 250 mhz and 300 mhz chips are interchangeable. So if you found a dual 250 pimm you can replace the individual chips with 300 mhz ones and change a resistor to get a dual 300. If you are braver you can usually overclock those to 350 mhz. For cheap, I'd go for the dually pimm then look for inexpensive processors.

hamei wrote: For cheap, I'd go for the dually pimm then look for inexpensive processors.

There's a dual 360 on eBay for $125 O.B.O.

I believe the seller is a regular on this forum.

Buy this . (not my auction)

QuicksilverG4 Offered me a dual 360Mhz and some other remains, to make my little box snappier. thanks for all the explanations. I now know better about those MIPS processors.