MP 1,1-5,1 2 Old Mac Pros, one with video issues that don't swap

Deschodt

macrumors member
Original poster
Jan 8, 2008
34
3
I "saved" 2x 2009 MP from the junk pile at work, initially with the idea to make myself a nice bench, and use one as a remote PC to get into work via VPN so I do not have to install all my company's spyware on my own mac. Ultimate performance not a requirement, but you know how this goes ;-)

One of them is 2.8 Mhz quad core, 1 gig ATI 5870, 12Gig mem. Works fine, been using it for months. The newer one I just "liberated" from work is a faster 3.x mhz (I forget) 6 core, so I figured I should use that one and transfer over the good stuff since it's faster. I did, moved the memory sticks, boot SSD, and the least noisy of both identical ATI video cards to it... Also put a new CR2032 battery on the PRAM, It booted fine and was great for a day, I thought I was a genius.

The next day I needed it for work and while it boots, it would not display video at all. Black screen. Worked the day before ! The odd thing is that I moved the GOOD silent ATI card to it that worked A-Ok on the other mac pro for months, and the louder other ATI to the original Pro (which also still works). I can keep swapping components (and verified the video card is Ok) but it's strange and I know both cards work since I swapped them around a few times and the newer Pro worked for bit with that card. Is there a maneuver I'm missing here ? I have not zapped the PRAM but it worked the day before and the battery is new. I'm connected via mini port, not DVI, maybe I'll try another cable... Anything else ? Not the end of the world, 4 core vs 6 isn't crucial for RDP work - who cares, but now I'm annoyed and curious .

PS: amusingly I initially goofed and inserted the wrong SSD (a clone of my new Imac on Mojave). Guess what, it worked perfectly on the Macpro !! The screen background was off somewhat, but the thing booted and ran perfectly on Mojave !!! ;-)
 

MacUser2525

macrumors 68000
Mar 17, 2007
1,915
271
Canada
The machines are identical instead of removing/moving components around move the CPU tray. It will work in the other machine with no problem and it sounds like you have 2010 or later machines as the base processor for a 2009 is a 2.66 chip the later is a 2.8 and the only speeds your new machine 6 core can be is 3.06, 3.33, or 3.46ghz the only chips produced by Intel for that machine running over 3 ghz.

Edit: Oh and them 6 cores will not run properly in a 2009 machine unless it has been flashed to a 5,1 2010 model firmware.

Edit2: Now I read it again the 2.8 chip will never work in the 2009 model same as the first reason, it would need the flash to do so to.
 

Deschodt

macrumors member
Original poster
Jan 8, 2008
34
3
Thanks for your reply, though I'm a little confused by it. I didn't know you could easily move the CPU tray, but on your edit are you saying I shouldn't anyway because they're different years and it won't work without reflashing. Honestly I'm OK using the 2.8 quad core and not mess around with fixing the 6 at all - I was just curious what would cause the newer 6 to work perfectly for a day (with the 4s video card) and then no longer do video - and if I take its card back out and put it back in the 4, no problems... Sounds like hardware issues other than the video card (yet with a no vide symptom), maybe the PCI slot, so not sure I want to swap CPU or anything for a small gain.... I was wondering if one of you experts might come back with "Oh that's a common old MP thing, just do xxxx"... I need to find a wood guy to do a nice bench / shelf, it's ok if only one works. Just puzzling.
 

MacUser2525

macrumors 68000
Mar 17, 2007
1,915
271
Canada
Thanks for your reply, though I'm a little confused by it. I didn't know you could easily move the CPU tray, but on your edit are you saying I shouldn't anyway because they're different years and it won't work without reflashing. Honestly I'm OK using the 2.8 quad core and not mess around with fixing the 6 at all - I was just curious what would cause the newer 6 to work perfectly for a day (with the 4s video card) and then no longer do video - and if I take its card back out and put it back in the 4, no problems... Sounds like hardware issues other than the video card (yet with a no vide symptom), maybe the PCI slot, so not sure I want to swap CPU or anything for a small gain.... I was wondering if one of you experts might come back with "Oh that's a common old MP thing, just do xxxx"... I need to find a wood guy to do a nice bench / shelf, it's ok if only one works. Just puzzling.
No my edits are telling you why I think you have a 2010 or later model. The chips you mention having seen will only run in a stock 2010 or later machine and a 2009 flashed with that firmware. The video problem who knows when I built my new machine I type this on connecting the monitor sitting next to it would not let the machine boot. Without it the machine is rock solid, computers are a strange thing some of the time they will work perfectly then like you have discovered will not work with the same part. Rather than chasing a solution that will never come use it the way they will work the best. Silent video card and fastest components in the machine that has the 6 core tray where the video will work is best.

Edit: CPU swap for small gain, you will get more than 50% improvement in raw speed calculations that can be done. You are adding two more cores that are able to be used by the software being run at a higher than the 2.8 speed, so you get that for a boosted percentage to. Plus the 6 core chips are the next generation with a better process with lower voltages used meaning less power consumed for that increase in processing.
 
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Deschodt

macrumors member
Original poster
Jan 8, 2008
34
3
I should have said "I'm not sure I did". I have no screen so I'm running blind. I've done command+option+P+R a few times but no clue (visual or audible) if that did anything... I replaced the PRAM battery first thing so I would think that zapped it for sure, found an old stock video 512mb card, tried that one also, tried both good ATI 1G cards, tried different slots, but the 6 core machine flat out does not display video anymore. It worked for a day. I guess something died. That's OK... I'm not going to bother moving CPUs around for a modest gain on a PC used for RDP only, it'll be a parts box I guess and leg 2 of my bench ! The other one works great for what I need it for !
 

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