SGI: Hardware

Hi

As you can see from my signature I'm blessed/cursed with one Onyx2 rack, one Origin2k deskside and one Onyx2 deskside. The Onyx2 rack is actually an O2k but I have a graphics module with skins for it. The rack is in storage and it will require some work to get all the parts together and fire up a working system.

Now, I've found someone who would like my racked system and I'm trying to decide whether I should keep it or not.

What do I gain by having the rack with a proper graphics module over linking the the two desksides together(I have all needed cables)?

I realize that the main difference will be in the capability of the graphis side of the Onyx2 deskside and the fancy display on the O2k rack. But exactly what are those differences?

I've done some reading up.

The graphics module in the rack will hold two graphics board sets (pipelines) one with two raster manager(RM) boards and one with up to four RM boards.
The deskside will hold one pipeline with two RM boards.

Assume that I will use this as a single seat system.

Obviously less texture memory will reduce performance, will it also reduce maximum resolution?
Can the two pipelines of the graphics module be combined for more perfomance?

Pontus wrote: I'm blessed/cursed with one Onyx2 rack, one Origin2k deskside and one Onyx2 deskside........What do I gain by having the rack with a proper graphics module over linking the the two desksides together(I have all needed cables)?

Unfortunately you can't CrayLink an Onyx2 Deskside. In order to shoehorn in the graphics boards into an Onyx2 Deskside they omitted the slot/circuitry for the second required-to-craylink router board.

Either of these threads might shed a little additional light on the issue:
viewtopic.php?f=4&t=16721904&p=7309092&#p7309092
viewtopic.php?f=10&t=16723803&start=15#p7326607

Aww.. chucks!

I could have sworn that I had seen a picture of an Onyx2 deskside craylinked with "something". If this is not possible, what is the little hatch in the front that access the routerboard for?

So.. lets talk graphics instead, how does the deskside compare with the full graphics module?

Pontus wrote: So.. lets talk graphics instead, how does the deskside compare with the full graphics module?

it just has less slots. same as with the cpu but if you're not going to use more than what the deskside needs you're totally fine

Pontus wrote: I could have sworn that I had seen a picture of an Onyx2 deskside craylinked with "something". If this is not possible, what is the little hatch in the front that access the routerboard for?

I'd suspect it's because they used the same molds as the O2k Deskside (and just switched the color to purple).

Pontus wrote: So.. lets talk graphics instead, how does the deskside compare with the full graphics module?

Previously Pontus wrote: Obviously less texture memory will reduce performance, will it also reduce maximum resolution? Can the two pipelines of the graphics module be combined for more perfomance?

With the Graphics Module you can have two pipes. The second pipe is roughly equivalent to what the deskside offers - room for two Raster Managers. The first pipe in a Graphics Module has room for four Raster Managers. Increasing the number of Raster Managers does have an effect on performance: viewtopic.php?f=3&t=16722836&start=15#p7319524 - read through the thread for details on what the numbers mean.

Increasing the number of Raster Managers / texture memory doesn't have an effect on the maximum resolution the pipe can display. The display resolution is controlled by the Display Generator, which has a maximum *output* bandwidth of 300 Mpix/sec (enough for two 1920x1080_60 displays, but not enough for two at 1920x1200_60).

You can combine the output of both pipes in a Graphics Module. If you want to do it in hardware you'll need a pair of DG5/DPLEX display managers (and likely an application that supports the hardware). You can also do it in software. The quick-n-dirty method would be xinerama. The big downside to xinerama is only the primary pipe can display OpenGL graphics. The better method would be SGI's OpenGL Multipipe software . OMP works very well, isn't to difficult to setup/configure, and depending on the configuration you choose, allows OpenGL graphics to be displayed across both pipes .

recondas wrote: With the Graphics Module you can have two pipes. The second pipe is roughly equivalent to what the deskside offers - room for two Raster Managers. The first pipe in a Graphics Module has room for four Raster Managers.

The display resolution is controlled by the Display Generator, which has a maximum bandwidth of 300 Mpix/sec (*just* enough for two 1920x1080_60 displays, but not enough for two at 1920x1200_60).

But probably enough for two 1920x1200 @ 50hz displays Is that the four-RM pipe or the two-RM pipe ? Or does the number of raster managers matter since the limiting factor is the display mangler ?

hamei wrote: But probably enough for two 1920x1200 @ 50hz displays

56Hz, IIRC. So close, but no cigar. Most panels wont sync to that.

hamei wrote: Is that the four-RM pipe or the two-RM pipe ? Or does the number of raster managers matter since the limiting factor is the display mangler ?

With more RMs you can have more features (pixel depth etc) and resolution too I think. But the limitation (as Recondas said) is the bandwidth of the pixel bus between the RMs and the DG. A deskside (2 RMs) can push enough pixels to max it out.

FWIW: A couple of years ago I had the opportunity to buy an Onyx2 rack. At the time I had an O2K deskside and an Onyx deskside and thought the rack might save some space (they're stacked after all). Turns out the footprint of the Onyx2 rack equals two desksides. This wasn't an improvement and I passed on the rack.

Me, I prefer the desksides. They allow you to 'taste' the architecture as good as the racks while taking up considerably less space. Which means I can have more

I'll offer Pontus the possibility of a third InfiniteReality solution. Sell the Deskside, the rack compute module and the rack. Use the money to buy quad-processor O300, a KTown2, a set of G-Brick panels, a G-Brick L2 module and a Numalink cable. Stack the O300 on top of the rackless Graphics Module/G-Brick. Same floor space as the Deskside, all the graphics horsepower of a rack Onyx2, and improved compute power (with the ability to take advantage of the extras that come with IP35-generation hardware - USB, SATA, firewire, etc.)

The conversion from Graphics module to G-Brick is bolt-on/plug-in - no solder or firmware incantations involved.

Thanks recondas, your advice is most welcomed. Also thanks to jan-jaap

I've decided to send the rack and graphics module on its way, the space it clears will be much appreciated Also the new owner is actually the one who bought the system to the hospital that gave it to me. It kinda feels right, it has come full circle.

recondas: a system much like that swooshed by an auction site here in Sweden four years ago, waay over my price range. Next time it might have come down to hobby-friendly prices. After all, bjornl has succeeded in acquiring one.

An Onyx2 deskside in Sweden.
Now that's a rare sight...

Oh,and I'd love one myself.

Speaking of alternate setups. I read that fellow countryman bjornl has successfully connected an Origin200 with a Graphics module: viewtopic.php?f=14&t=16726726

Which left me wondering, could a graphics module be hooked up to an Octane?

Pontus wrote: Which left me wondering, could a graphics module be hooked up to an Octane?

An x-town board is the compute end of the Graphics Module CrayLink connection. It uses the same standard half-height XIO configuration as the Octane: Whether or not it'll work will remains an exercise for someone with a strong sense of adventure.

Pontus wrote: Speaking of alternate setups. I read that fellow countryman bjornl has successfully connected an Origin200 with a Graphics module: viewtopic.php?f=14&t=16726726

Which left me wondering, could a graphics module be hooked up to an Octane?

Physically yes, XTOWN board (with swapped compression actuator) in the Octane and a KTOWN in the Graphics Module.

I doubt if KONA support is present in the IP30 IRIX package, and having played around with the IRIX modules a little I can tell you that if support wasn't built in from SGI then there's probably some unsatisfied dependencies or other gotchas lurking somewhere in the modules. Rumor has it that were someone to get their hands on a leaked copy of the IRIX 6.5 source it doesn't have the interesting stuff like graphics and hardware support either - though I would love that to be proven wrong.

Unless SGI disabled it in IRIX you should also be able to put a XTOWN in a deskside Onyx and have a "MiniMonster Station" with multiple pipes.

Best way might be to get a KTOWN2 and connect your Graphics Module up to an Origin300. They're cheap, fast, and a more convenient size than an Octane. You also get the possibility of 4 CPUs.

Even if this was possible, what would be the advantage of either an o300 or octane2 over an onyx2?