FB-dimm temperatures help needed

[mactune]

Hi,
I got a mac Pro 1.1, recently upgraded CPU's to Xeons X5365, flashed pc radeonHd 5770, SanDisk SSD, managed to install ML 10.8. Everything is running perfectly, I can even do the updates however one thing bothers me a bit. Temp monitor shows that my RAM temp is a bit high. I got 8x2GB modules and the temperatures are between ~68 to ~77 depending on the location. Is this something to worry about? I got no problems whatsoever, it is rock stable.
Just curious if it has any long term impact and if I should play with SMC fan control. Any help is much appreciated.
Thanks,

[paulrbeers]

Originally Posted by mactune

Hi,
I got a mac Pro 1.1, recently upgraded CPU's to Xeons X5365, flashed pc radeonHd 5770, SanDisk SSD, managed to install ML 10.8. Everything is running perfectly, I can even do the updates however one thing bothers me a bit. Temp monitor shows that my RAM temp is a bit high. I got 8x2GB modules and the temperatures are between ~68 to ~77 depending on the location. Is this something to worry about? I got no problems whatsoever, it is rock stable.
Just curious if it has any long term impact and if I should play with SMC fan control. Any help is much appreciated.
Thanks,

No. Mine on the top board run between 75-80 and on the lower board between 70-75. It's been like this for almost a year and I max out my RAM regularly. In fact my Mac Pro 1,1 has been converting videos via handbrake for the last two weeks almost constantly with no issues.

[mactune]

Thanks. I was worried that it could have impact down the line.

[El Awesome]

If you're worried you can still take a fan control app and make the intake fan run faster (will increase the noise level)

[GermanyChris]

I prefer to kick up the exhaust fan. The intake fan has to blow over the processor heat sinks before hitting the RAM, but the exhaust fan pulls the nicely contained hot air out

[Tesselator]

Yeah, Apple's native fan profile walks a line between goofy and insane.

My Profile in blue on the left. Temperatures on the top, Fan speeds on the bottom.
Apple's Profile in salmon on the right. Temperatures on the top, Fan speeds on the bottom.

My way is just to set all fans to the same speed and create multiple profiles differing by 100RPM each starting with 1000 and going up to 3000. Unlike Apple I don't think the fans should ever be below 1,000 unless you're using it outside in the snow or something. You can see clearly here that Apple's default profile while dynamic, keeps Northbridge at nearly 100˚C and the RAM between 65˚and 75˚C. That's too high. The OP is right, that will likely cause problems. Even while testing this I got a Soft Write Error to my TimeMachine:

Chris's idea of only cranking the exhaust fan works. It's a different sound for sure. Higher pitch and a tad less efficient. It also seems to increase the PSU fan and dust bunnies there are harder to clean. Still it works pretty good tho!

A lot better than Apple's... What were those guys thinking anyway...

[GermanyChris]

i can't hear the rear fan at 1k the same cannot be said for the others

[mactune]

Thanks Tesselator for detailed info. After I installed smcFanControl and set defaults to 1000rpm for each fan the temps look much better. I Also tried 2000rpm and for a second I thought it will lift off so much noise.
Much appreciated.

[Tesselator]

Originally Posted by mactune

Thanks Tesselator for detailed info. After I installed smcFanControl and set defaults to 1000rpm for each fan the temps look much better. I Also tried 2000rpm and for a second I thought it will lift off so much noise.
Much appreciated.

Yeah, 2,000 would be for when you needed to render some heavy animation frames during a summer heat-wave. I bounce mine between 1,000 and 1,300 mostly.