>| We have several 4D/20tg PIs, with differing data and instruction
>| cache sizes.
>| The largest have 32K data and 64K instruction, and these are still
>| quite useable machines for student work.
>| The smallest have 8K data and 16K instruction, and the lag-time
>| on the graphical login typeahead is almost unbearable. I'll not
>| even mention how bad they perform otherwise.
>| My question is, what is involved in upgrading the data and instruction
>| cache sizes of these machines? Is it a full CPU-board-type swap? Can
>| it even be done? $$??
>It seems more likely that the 32+64 systems are 4D/25's with
>a 20 MHz clock instead of the 12 MHz clock on the 20. A relatively
>small number of 4D/20's at the very end of their life were built
>using the 25 CPU board at the lower clock rate, and hence have
>a larger cache, but the performance difference of the cache
>alone really wasn't all that great.
>Look at the hinv output and see what it says about CPU speed.
All of the 32/64K systems list their processor as 12MHz IP6--4d/20, right?
Is it possible that hinv is lying to me on the suspect systems? Our sales
droid at the time sold them as 4d/20s--I'd be considerably surprised if it
were to turn out they're actually 4d/25s and we got more computer than we
paid for. ;-)
I've gotten *numerous* responses telling me to check the main memory size
(32MB on all the above systems) because that's the slowdown problem. But
I *know* it's not because they're *all* at 32MB regardless of the cache
size, but there's a noticeable difference between the machines' performance.
It would seem that I've gotten 3 of the 'relatively small number' of 4d/20s
with the 12MHz r3000 and the bigger caches.
Now, if the main memory size is the same on both of the machines in question,
and the performance difference in the cache size isn't all that great, what
else could be contributing to the exceptionally slow graphical startup/login
on the machines with the smaller cache? Swap is the same, they're all
running 4.0.5a; I'm at a loss. Could the chip revisions or graphics
revisions play a significant role here?
Quote:>There are no 20 to 25 upgrades available anydore, as far as I know,
>but upgrades to the 4D/35 (36 MHz R300A, 64+64 cache) are probably
A kindly SGI fellow sent me the part number for a refurbished 4d/25 upgrade:
HUR-4D25A. I can't speak for the availability, but I understand it lists
for $3500. The 4d/35 upgrade Dave mentions goes for $9000 list, I believe.
|| Steve Rikli ||| Visualization Lab ||
|| 409-845-3465 ||| College Station, TX 77843-3137 ||