Jump to content

Recommended Posts

hello.. recently i found a powermac g5 Quad. i thought it could be a nice computer, well it is to some extend but i found that it's way more noisy than my older g5.. (dual processors 2ghz model) when idle the computer is quiet.. but if i watch flash video in tenfourfox the fans will go up around 2000 rpm.. is it normal for this model ? Also i let the computer on at night when i sleep.. and when i wake up i see that cpu A is around 10 Celsius warmer than B ( CPU A core1=43 CPU A core2=45 CPU B core1=33 CPU B core2=33 ) what i do to get more even temperature is to load a program that use 4 cores at 100% like altivec fractal demo.. then the difference between cpu is more like 6 Celsius... I have opened the computer to see leaks but didnt see anything.. do anyone else experiment these behavior with the quad ? let me know..

Link to post
Share on other sites

I don't have a Quad, alas, but have worked with three dual G5s and still use one daily and another several times a week.

 

A handful of ideas/ responses:

 

1. Different temperatures are normal, but high fan speed may be a sign of coolant leakage. Are there any other odd behaviours? Have you had a good look around in there? Is there a sackful of dust clogging the airways (this DOES happen with the G5s)?

2. What are the temperature peaks when running hard? D/L Temperature Monitor (free) to, well, monitor the temps.

3. What is the energy system preference set on, Highest, Auto or Reduced? Adjustments here can make a big difference.

4. The CPU cooling system may need to be serviced and/or recalibrated with the relevant Service Diagnostics software.

Link to post
Share on other sites

i cleaned the inside while looking for leaking fluid.. there is no dust anymore stopping the air i think.. i always set the energy system to automatic.. the system seem to run fine.. no kernel panic it just get loud sometime mostly while watching flash stuff , the old g5 dp didnt do that .. when i load all the 4 cores to 100% it will peak around 77 celcius on cpu1 core b and cool down to 65.. and the rest of the cores will be around 60-61.. fans will go up to 2700 rpm under full load.. is it normal ?

Link to post
Share on other sites

I have a quad and two 2.7 GHz power mac G5's, working great

 

- Set the energy system to highest

- Ad enough ram ( max ram )

- Keep a lot of free space

 

Keep the fans, ram, graphic card,.... dust free, all this is easy to accass

 

And because it's hard to access the power supply, use compressed air to clean as much as possible the power supply

Link to post
Share on other sites

There are a couple of members with long experience of the Quad G5, such as ClassicHasClass and Applefreak. I have no doubt that both will respond once having read your post, but I seem to recall in an exchange with CHC myself that his Quad operates at significantly lower temperatures. 10º in the G5 CPU makes all the difference as far as fan speed is concerned.

 

I suspect that individual processors have different heat characteristics, and that this has to be factored into talk about what machine gets how hot, alongside of things like heatsink compound and dust. That one G5 does x does not means than another identical unit will do x as well, even when properly tweaked. I had, for instance, a dual 1.8 that ran much cooler than a dual 2.0, and I have a dual 2.3 (early 2005) that runs cooler than the 2.0 and is comparable to the 1.8. The 2.0 is the noisiest of the lot, and though for the most part it is a quiet machine for what I do on it (mostly office stuff), the fans do kick in big-time if the temperatures get up into the high 60s. Invariably, this happens on the web, and Flash is certainly a factor there.

 

Thermal tolerances are seemingly set/ tweaked by thermal calibration in software, and these can be checked in Temperature Monitor, which was already mentioned. The upper limit for my G5s tends to be high 70s or thereabouts (slightly different for the different machines, BTW), so if your machine is getting up there, it does need the cooling action of the fans, else damage will result.

 

Whether Flash "ought" to be causing these behaviours is something that others will no doubt weigh in on in due course, but we all know the Flash is crappy software that strains older hardware to the limit, and we had that confirmed by Apple's abandoning it for the likes of the ARM chip. It would be interesting to try HTML5 on the same site and see the difference.

 

The liquid cooling, of course, is a complicating factor in your case (are the pumps working, is there leakage, is the level adequate and is the coolant contaminated), but in my experience, the simpler resort of doing a thermal calibration can help a great deal with the fans. It was certainly so with a dual 1.8Ghz machine that I used for a while. It may be that yours is also one of those cases. You'd need to locate the appropriate "Apple Service Diagnostics" disk image "out there" to do the business, of course, and you would need the version for your machine or era specifically, but if I were you, and dust etc. had definitely been excluded as cause of this effect, I would try recalibration next. It can't do the machine harm (it is working now on the basis of the same process done in the factory) and it might do it a lot of good. Takes about 90 mins, during which the fans will run full blast, so plan to go out.... Essentially, if the physical characteristics of the cooling system have changed due to ageing, it would follow that the software controlling that system could likely use better information about those changed characteristics.

Link to post
Share on other sites

flash doesnt get the cpu to reach 70.. i will get in the 60s but it mostly stay in the 50s.. i get 70 fron a fractal benchmark that use 4 cores at 100% ... but still flash video.. will get the fans to speedup at around 2000+ rpms wich is kind of loud compared to my older g5 dp mac... i guess there is not much to do unless i try to dissemble the lcs for inspection..

Link to post
Share on other sites

tested the Quad (system 10.4.11, 8GB ram, HDD 2 x 1TB) with a full 3D rendering ( LightWorks ) of a building

Activity Monitor

all 4 processors fully used, for a while during rendering

 

quad_proc_rend.jpg

 

istatpro

 

quad_temp.jpg

 

if the rpm and temperature of A and B are more or less equal, > good

rpm of the A en B pump ± equal, (equal up, equal down) no worry about leaks

 

30 minutes later, but it's the same as 3 à 4 minutes later

 

quad_temp2.jpg

 

i always choose to set the energy system to highest,

because the fans are spinning at low rate from the beginning

and there are less peaks,

temperatures are fairly stable

Link to post
Share on other sites

Even while my quad is building TenFourFox (which uses make -j2), core temperature doesn't get much higher than 60 C. CPU utilization is around 40-60% on all cores at that time. At idle (I run my system in reduced mode ordinarily to extend the life of the unit and reduce power usage), most cores are between 38 and 48 C. At full tilt it roars. At idle it's quieter than the MDD.

 

Note my system is in a relatively cool room with indirect sun and it can ventilate into the center of the room, so ambient temperature and ability to vent do play a role.

Link to post
Share on other sites

i see.. well i guess its getting a bigger problem.. your quad run quieter and cooler..

the flash video was this : http://www.onf.ca/film/L_age_de_la_machine/

 

i have the one pump version, i think 10 Celsius difference on cpuA core 2 is a bigger problem than i thought.. i tried to calibrate with the asd 2.6.3 discs.. everything passed but nothing changed.. i guess i could try to reapply thermal paste ? someone did that i think.. but everything is so sealed not sure how to do it..

Link to post
Share on other sites

Dis-assembly for application of new thermal compound is not hard to do, and the fears of some about doing it that can be found here and there seem to me to be absurdly overblown. There are some pictorial guides to doing it online. You do, however, need a modest toolkit, and especially one long, thin, specialist screwdriver that you are not likely to have in the average set of screwdrivers. It needs to be as slender as possible and long enough to reach the logic board from the top. There are, as I recall, six or possibly eight bolts to be loosened (not removed); it helps to know exactly where these are from the online guides, as there are some that you don't need to touch and that are best left as is.

 

A screwdriver shaft that can take a thumbwrench for cracking the bolts holding the processors down is ideal (e.g., like the hexaconal shaft on the driver I use); the extra torque helps at the beginning, not so much because the assembly is screwed down so tight as because of the particular form of bolt used. (There is a "spreader" used in the assembly, the working of which is much like a rawl plug — I don't know what they are called — and this seems to need a little "persuasion" sometimes before it moves).

 

On an air-cooled unit, the whole mechanical operation described takes less than an hour, followed by calibration, of course. The main difficulty I had when I did my first was in removing the cosmetic cover. That little plastic rivet just did not want to come out! The rest was straightforward.

 

Calibration after all is done can be shortened by selecting thermal calibration only (thus avoiding the lengthy RAM tests, etc.) in the ASD settings. Maybe doable in 90-100 mins., top to tail?

Link to post
Share on other sites

yes.. i did.. it's strange i leaved the computer for a couple of hours off and i decided to try again.. the computer was very quiet and the temperature of each cpu seemed close of each other. i leaved it on for a full day then the next morning i see the 10 celcius difference between cpu again and the computer is noisier.. i used it for some time and the noise become more tolerable. it seem it doesnt like to idle for a long time ? the liquid get thick ? im not sure..

Link to post
Share on other sites

i redid the thermal paste again hehe.. and the results are strange.. now the temps are all equal during idle.. but now under heavy load it's core 2 on cpu 2 that is 10C warmer.. before it was core 2 on cpu1.. so maybe there is not enough liquid to cool down all the cores.. not sure.. ill leave it like that for a few days..

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...