jcmiller@hydra.unm.edu (Jeff Miller) (07/03/90)
Hello fellow SGI users!! I have a couple of hardware questions for all of you GURU's out there: (1) What is involved in upgrading a 4D/20 to a 4D/25? I am willing to perform the surgery myself. I believe that it involves replacing the R3000 and R3010 CPU and FPU with faster components and, of course, faster RAM. In addition, there seems to be room to install 64Kb of cache RAM in place of the existing 8Kb cache. Is there any special hardware swith to tell the CPU that it has more cache? ( Yes, I know the proceding proposal definitely voids my warranty-- if I still had one :-) (2) What are the power requirements for a fully loaded 4D/20 w/o hard drive or tape? (3) How much airflow is a "safe" minimum for the SGI? (in cu ft / min) ? Thanx in advance!! jcmiller@hydra.unm.edu "There are two types of people in the world--fast and hungry"
olson@anchor.esd.sgi.com (Dave Olson) (07/04/90)
jcmiller@hydra.unm.edu (Jeff Miller) writes: | Hello fellow SGI users!! | | I have a couple of hardware questions for all of you GURU's out there: | | (1) What is involved in upgrading a 4D/20 to a 4D/25? I am willing to perform | the surgery myself. I believe that it involves replacing the R3000 and R3010 | CPU and FPU with faster components and, of course, faster RAM. In addition, | there seems to be room to install 64Kb of cache RAM in place of the existing | 8Kb cache. Is there any special hardware swith to tell the CPU that it has | more cache? | ( Yes, I know the proceding proposal definitely voids my warranty-- if I | still had one :-) I won't speak to the rest, but some other things that you get with a 4D25 are a faster SCSI chip, and a new I/O controller chip. The combination boosts disk throughput considerably. Since the I/O chip is an SGI chip, you can't just buy one. The SCSI chip is the WD 33C93A, instead of the 33C93. Just changing the SCSI chip won't help a whole lot without the new I/O chip (I seem to recall about 10% improvement with just the 93A). The types of the I/O and SCSI chips are determined independently of each other. I also seem to recall that there was some minor board layout required to accomodate the higher clock rate, and some PAL changes. The cache is sized at boot time; I don't know if the 4D20 cpu board really supports more cache than is present; I am not a hardware person. And, as you note, you have completely violated your warranty, and if you blow it, you lose... -- Dave Olson Life would be so much easier if we could just look at the source code.