Ubuntu on a G5 Mac? (Now with bonus blown power supply) - Page 1
Forum section: electronics / general

author: gildasd
author_rank: Frequent Contributor
timestamp: September 24, 2015, 01:45:10 pm
content: For my bachelor's degree, I have to do a bit of basic CFD (simple shapes, cubes and the like).I will be using the most basic visualisation as the numbers are my primary concern.The best "free" software for students seems to be OpenFoam that has an Ubuntu build:http://www.openfoam.org/download/My mac is twin G5 PowerMac with 4gigs of ram that unused. It works great, quiet and very reliable.I was wondering if I could do a Ubuntu install and run OpenFoam on it. What pitfalls might a newb encounter doing so?http://www.ubuntu.com/downloadThere are 3 current versions, so I don't even know where to startThanks!Background:This is the same project, but more refined, referred to in a previous topic that I am trying to get off the ground on a shoe string:https://www.eevblog.com/forum/beginners/datalogging-with-arduino/That part is solved with; UNOs, Adafruit dataloggers and I2C sensors. Currently evaluating various software solutions.I know that a 200 euro PC setup in a cardboard box would be faster _ I don't have 200€ as a side effect of being a student and renovating a house for wifey and daughter.I will be testing the correlation of CFD, Windtunnel and real world data in the nautical domain for ship superstructures - fun for all the family!I don't care if the CFD takes 8 hours instead of 2, because I can leave it running day and night.The final CFD visualisation runs for the presentation will be done with an 8 node, 32 core setup - that I don't get a lot of time on - so I need to iterate before.The CFD is really basic, mostly a single cube a various angles and wind speeds in the non compressible region.

author: Mechanical Menace
author_rank: Super Contributor
timestamp: September 24, 2015, 02:47:50 pm
content: The biggest pitfall I can think of is you may have to build openfoam and some of it's dependencies yourself. It's not impossible that there's a PowerPC PPA out there but I sort of doubt anyone would bother any more.

author: gildasd
author_rank: Frequent Contributor
timestamp: September 24, 2015, 03:03:59 pm
content: Quote from: Mechanical Menace on September 24, 2015, 02:47:50 pmIs because of the non intel CPU?I'm also looking at ANSYS Student pack on PC as an alternate solution but that brings a whole lot of workflow issues: can't work on the PC when it's CFDing.

author: Mechanical Menace
author_rank: Super Contributor
timestamp: September 24, 2015, 03:43:17 pm
content: Quote from: gildasd on September 24, 2015, 03:03:59 pmYeah. But it does look like there's an official PPA for Ubuntu 14.04, seehttp://www.openfoam.org/download/ubuntu.php.That may have a PPC build as according to the website they do support PPC. If not you can just build it following this guidehttp://www.openfoam.org/download/source.phpQuoteBy now there's a good chance your x86 based PC is much faster than the G5 though, especially if you can use it's GPU for the CFD work. I know OpenFoam can do that using various plugins but I can't vouch for how good the unofficial Windows builds work (I'm guessing you're on Windows and opposed to dual booting as you want to use your G5 for Ubuntu lol). Anything stopping you using the G5 for the rest of your work while that is chugging away?

author: gildasd
author_rank: Frequent Contributor
timestamp: September 24, 2015, 03:59:56 pm
content: I have all my CAD/presentation/science tools on my PC, and I need those to study while the G5 is chugging away...Switching that and all the other stuff over to the G5 would be a major workflow issue now that the Uni year has started (first paper on relative stability in an automatic system due next Wednesday).And my PC is 5 years old...Athlon 64 X2 6000+ at 3Ghz, 4gigs of Ram and a Radeon HD 7700 Series 1gb Ram - so about par with the G5...Would you recommend any other CFD product for simple stuff? Fundamentally, I only need the drag results.

author: Mechanical Menace
author_rank: Super Contributor
timestamp: September 24, 2015, 04:15:31 pm
content: Quote from: gildasd on September 24, 2015, 03:59:56 pmI'd stick with openfoam on the G5 then. You do sound like you're much more patient than me too which would help, and you seem well aware that even simple things may take days to complete. And tbh other software wouldn't be much faster on the same platforms. Getting a hang of running this sort of stuff on Linux could be advantageous for you too. If you end up doing this sort of thing a lot the major number crunching will almost certainly be done on a *nix of some type even if your front end tools are all on Windows.My experience with this stuff is more helping get people up and running on systems, but I can tell you that it scales well and other comparable or better alternatives would (in my experience) be expensive to move to the final platform. If you need any help getting it installed on your G5 or the cluster and getting going with it feel free to ask or PM me, but alas I'm not clever enough to offer any advice on the actual work you're doing lol.

author: gildasd
author_rank: Frequent Contributor
timestamp: September 24, 2015, 04:26:36 pm
content: Quote from: Mechanical Menace on September 24, 2015, 04:15:31 pmCheers!First question, the G5 has an IOs that I want to keep (ex boss gave me a Adobe licence he could not upgrade), so is a dual boot doable, or do I need another HDD?

author: Mechanical Menace
author_rank: Super Contributor
timestamp: September 24, 2015, 05:03:44 pm
content: A dual boot is doable, to the best of my knowledge the Ubuntu installer should still deal with the bootloader for you. But I'd really advise backing up your HDD and then resizing the needed partitions using Apples tools before booting the installer. I have no idea how well HFS+ is handled in Linux sorry. If you want to be extra safe use another HDD, but if you've an old one lying around that should do. An 80 gig drive should be more than enough.

author: Delta
author_rank: Super Contributor
timestamp: September 24, 2015, 05:31:59 pm
content: Erm, what is CFD? 😂I did gooooooogle it but there are loads of results for that TLI....

author: Rasz
author_rank: Super Contributor
timestamp: September 24, 2015, 05:41:29 pm
content: Quote from: gildasd on September 24, 2015, 01:45:10 pmno, a FREE hand me down/taken from a garbage bin at the recycling center computer from 2008 will be faster.Quote from: Delta on September 24, 2015, 05:31:59 pmno you didnt, google spits correct answer as a first result

author: gildasd
author_rank: Frequent Contributor
timestamp: September 24, 2015, 05:54:41 pm
content: Quote from: Mechanical Menace on September 24, 2015, 05:03:44 pmOk, I'll follow your advice.I have got a 36Gb 10000Rpm disk that would be ok-ish.Now to the man cave!

author: Delta
author_rank: Super Contributor
timestamp: September 24, 2015, 06:06:40 pm
content: Quote from: Rasz on September 24, 2015, 05:41:29 pmYes I did, but thanks for assuming you know more about what I do or don't do than I do. I just didn't think "Contract for difference" was related to an electronics forum...

author: helius
author_rank: Super Contributor
timestamp: September 24, 2015, 06:19:22 pm
content: Computational Fluid Dynamicsyw(it's easy to forget that Google is tricking you with its search results, customizing them to what it thinks you like; among other consequences, it means that searching Google to decide which thing is "most popular" is invalid)

author: gildasd
author_rank: Frequent Contributor
timestamp: September 24, 2015, 06:43:41 pm
content: Quote from: Rasz on September 24, 2015, 05:41:29 pmThis is a student town, even P4's get resold for 100€ to stupid people who just want something to write papers on... So forget getting a Core Duo.It's illegal to take anything from the recycling centrer once it's out of the car, it's considered stealing and they will can the cops and give them the footage (probably get a bonus too).I don't trust stuff that's too cheap, could be stolen - I can't take the risk with my degree...I can get small stuff like old ram sticks and older HDD's from the return bin a my in-laws work. It's usually pretty crap/low speed, but it works.Spending even 100€ just to go a bit faster is silly if the P5 works, that's money that could be spent on more/better sensors or resin to smooth out the cubes etc...Thanks for the ideas anyhow!

author: Delta
author_rank: Super Contributor
timestamp: September 24, 2015, 09:31:31 pm
content: Quote from: helius on September 24, 2015, 06:19:22 pmThank you!

author: gildasd
author_rank: Frequent Contributor
timestamp: September 27, 2015, 05:05:48 pm
content: Deep breath.My super reliable G5's power supply gave me the "bang magic smoke treatment" on 1st power-up...Should Ior?time, hope it's just a blow capacitor.Fucksocks!

author: gildasd
author_rank: Frequent Contributor
timestamp: September 27, 2015, 05:48:24 pm
content: Hello hello hello, this just dropped out...Edit:Underside of a G5 power supply PCB:The 2 circles are serious bodge jobs.The 4 dots above of centre are the pins to the power regulator (?) that blew...I'm thinking of a conductive dust short... Should I be looking for anything else?

author: gildasd
author_rank: Frequent Contributor
timestamp: September 27, 2015, 07:22:35 pm
content: Found more pieces...Whatever that is, it hjas truly blown it's top of.Off to find this part!Found it;http://www.digikey.be/product-detail/en/TOP249Y/TOP249Y-ND/1007591PMIC - AC DC Converters, Offline Switchers

author: SeanB
author_rank: Super Contributor
timestamp: September 27, 2015, 08:24:05 pm
content: TOP 24x series SMPS units, very common for them to blow up, mostly from failed capacitors on the primary side supply and failed high value start up resistors. Changed a few in equipment, they are commonly available even here.

author: gildasd
author_rank: Frequent Contributor
timestamp: September 27, 2015, 08:54:59 pm
content: Quote from: SeanB on September 27, 2015, 08:24:05 pmDid a bit of research.On a G5, when this component fails, it's usually the last domino in a chain failure. Changing it usually does nothing and even if it does work, it will blow again shortly.All the caps are good on mine, so are the resistors, I tested a few, and all is OK, but it's apparently not worth the bother.I can get another G5 with a blown motherboard from a friend (he was supposed to do a hackintosh, but life got in the way) and use it's supply.If that does not work out, I'll use this method:http://www.javrullan.es/en/PowerMac_G5_PSU_Repair.htmlstuffing an ATX PC supply into the G5...I will sadly lose the ability to use the Mac screen.

author: gildasd
author_rank: Frequent Contributor
timestamp: September 28, 2015, 05:14:01 pm
content: Could I do something to limit to max out? Something that would limit output to 250W preventing repeats?

author: gildasd
author_rank: Frequent Contributor
timestamp: October 02, 2015, 09:52:40 am
content: Speaking to myself again...By chance, I managed to fix the "Donor G5" by simply cleaning it and changing the motherboard battery...It's a dual 2.7Ghz water-cooled with 7 Gig of ram. That will do nicelythankyou.However, as you can see on the second picture, one of the secondary heat pipe coolers has developed a leak. This is quite old and seem to not have had any influence so far...Is there a way to fix a heat pipe? I was thinking of partially filling it with alcohol and soldering it shut...Edit:Got the CPU's out.No real leak or oxidation on the water cooling system, good news, the heat pipe seems to have been badly crimped... So It was leaking from day 1.It worked for 6 years in an office as such, so hopefully it can hold out for 6 more months. If not, I have 2Ghz replacementsOut of curiosity, I checked Apple Belgium's policy for expired products with a possibly dangerous defect (liquid on power supply + alloy case + toddler = PR nightmare).And while Apple US offer about a 2400$ credit on this very defect, Apple Belgium's website policy sound like "Product 2 years or older? Fuck you! Hahaha"...

author: gildasd
author_rank: Frequent Contributor
timestamp: October 02, 2015, 07:58:03 pm
content: Scan of the underside of the CPU boards:This G5 has some really unnecessary complexity that makes me shake my head...Cooling the memory on CPU sub board is a clear example:Cooling from the OTHER side of the board is thermodynamically unfathomable. It leads to using a complex heat tube with a complex mounting.An off the shelf mid range GPU cooler could have probably yielded the same results with far less warranty issues...