[ColanderCombo]

I notice that when installed in a Deskside Onyx, the maximum number of IR RM6 boards seems to be two, leaving two slots empty:

http://archive.irix.cc/sgistuff/hardware...ality.html

Does anyone know if this is an actual limit, or is it theoretically possible to install four RM6's in a deskside? If it is a real limit, is it because of power, cooling or is the KONA ready backplane actually missing connectors for the extra two slots?

[dexter1]

Hm, this sounds suspiciously similar to my Crimson RE system which support for only two RM4/RM5 raster boards. Well, support, you get a bridge board with only two connectors for each rasterboard. I think TriOx has tried 4 RM4's in a deskside system and it cooked itself after a week, but that is just rumors and hearsay since i also don't know what cooling tray he used ;-)

I would venture that it is power and heat related, and considering how rare the old raster boards are these days, don't try it out for the sake of it if you actually have such a system. While you're at it, buy or make filler boards for the empty raster slot spots so that the airflow will go over the raster boards.

[jan-jaap]

is it theoretically possible to install four RM6's in a deskside? If it is a real limit, is it because of power, cooling or is the KONA ready backplane actually missing connectors for the extra two slots?

It is possible (people have done it).

The Onyx IR needs the bigger 2400VA OLS, while the power consumption of a dual RM system is ~ 1500W from the wall, so power wise I think you're OK. But the deskside chassis can't provide enough airflow so you will cook it. Also, it's going to hit 'fastfan' in no time and then you don't want to be in the same room as that thing.

NB: if you have spare RM6 boards, or know someone who does: I need one or two to revive my own Onyx IR.

---

Hm, this sounds suspiciously similar to my Crimson RE system which support for only two RM4/RM5 raster boards. Well, support, you get a bridge board with only two connectors for each rasterboard. I think TriOx has tried 4 RM4's in a deskside system and it cooked itself after a week, but that is just rumors and hearsay since i also don't know what cooling tray he used ;-)

A 4-RM RealityEngine was possible, but like the Onyx, only in the tall racks.

If you've been close to a working 4D/380 "Predator" rack or looked at it's fan tray, you know the airflow in the rack is ... significant.

[ColanderCombo]

NB: if you have spare RM6 boards, or know someone who does: I need one or two to revive my own Onyx IR.

The recycler in Providence (mentioned here: https://forums.irixnet.org/thread-1366.html) has a selection of spare Onyx IR boards, including two RM6-16's. They used to have four, but I picked up a full boardset including two RM6's. I also grabbed the (skinless) deskside RE2 Onyx. I'd like to eventually be able to swap out the RE2 for the IR set, but I'm guessing that will require finding a KONA backplane, power and bulkhead connectors. We'll see once the system arrives!

It's nice to know that it's *possible* to use 4 board, obvious heat issues notwithstanding.

[TriOx]

Hi dexter1, wow you have a good memory. I did in fact cook 4x RM4 boards in the deskside. They all went stripy iirc and I don't think it even took more than a day or so.
I vaguely remember my apartment being quite hot, it was probably the summer and no AC, this didnt help I'm sure. I still have that Onyx deskside and could check which blower is in the tray. It started life as a VTX... Is there a reference for any different versions of blowers?

I remember the Crimson had two different versions, either 4x fan or 6x fan tray but not sure on Onyx.

edit: you know, I wonder if those RM4 boards could be fixed with trip to the oven for a reflow. I'll keep my eye open for some duds. Could a fun post lol

[ColanderCombo]

edit: you know, I wonder if those RM4 boards could be fixed with trip to the oven for a reflow. I'll keep my eye open for some duds. Could a fun post lol

I know RM4's at least are *very* heat sensitive and if the thermal adhesive on the asic's get soft enough that the heatsinks aren't making full contact with the chip it can flake out. I babysat a terminator Onyx about 15 years ago that would occasionally go stripey, and invariably if you pulled the RMs and wiggled around the heatsinks a bit things would get better for a while.

[TriOx]

edit: you know, I wonder if those RM4 boards could be fixed with trip to the oven for a reflow. I'll keep my eye open for some duds. Could a fun post lol

I know RM4's at least are *very* heat sensitive and if the thermal adhesive on the asic's get soft enough that the heatsinks aren't making full contact with the chip it can flake out. I babysat a terminator Onyx about 15 years ago that would occasionally go stripey, and invariably if you pulled the RMs and wiggled around the heatsinks a bit things would get better for a while.

Thanks for the tip! You know I never tried that wiggly trick. I just yarded them out and slid in a pair of RM5 and left it at that. At that time, The RM4 were easy to find and cheap so I didn't worry about it much. This fall I plan to fire up my Onyx for the first time in 12+ years, so this may come in handy.

Good luck in your IR upgrade, I hope the skinless RE2 chassis is Kona ready! At least it looks like it does have the upgraded OLS with red sticker.
https://photos.google.com/share/AF1QipPn...JXTEJYX3FB

I saw those IR boards too and dreamed a little about the doing the upgrade but I was hesitant to enter into the Kona backplane / power module hunt so early into my SGI revival.