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iMac 2010 - Super low Geekbench and Cinebench Scores

Cookie18

Cookie18

macrumors 6502a
Original poster
Sep 11, 2014
584
684
France
I have a 2010 27" iMac that I have been upgrading as a little project. I'm using it as a second display through Target Display Mode and as a secondary computer on my desk.

When I first got it I ran a Geekbench 5 test and it got slightly above the average of 519/1593 for the i5-760 in it. If I remember correctly it was something around 560/1620. I later swapped out the HDD for an SSD and I put a 2.5" HDD that I had lying around in the Optical Drive slot. I also upped the RAM from 8GB to 14GB by swapping out one of the 2GB sticks for an 8GB stick I also had lying around.

After the upgrades I ran Geekbench again and it got an abysmal 160/600. These are the rough numbers but obviously they are WAY off. I didn't think too much about it because I had already ordered an i7-870 to replace the i5 but it was still worrying.

Today I replaced the i5 with the i7 and I got a Geekbench score of 213/920 which is still insanely low. I figured it could be a software issue so I deleted and reinstalled Geekbench but got almost the same result. I installed Cinebench R20 and I got a score lower than my dual core 2012 MBP so that's way off too.

Does anybody have any ideas what could be causing this? One of the heat sensor cables got messed up during the change so it does the full blast fans on start up before Mac Fan Control brings them down. For the tests I put the fans on full blast to ensure it was thermal throttling. Should I reinstall Mac OS?
 
wilberforce said:
Do you have high CPU usage from system process kernel_task?

(Activity Monitor - View - All Processes)
Click to expand...

No, kernal_task is sitting at around 0.1-0.5% right now. Total system+user usage is a little less than 1%. I ran Geekbench and Cinebench about 5 minutes ago after putting the original RAM back in and got the same results.
 
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I'm no pro,
But if you mess with a thermal controller by mistake, it throttles the CPU. You have to fix the heat sensor cables.
 
It really sounds like it is a problem with the new ram module. It could be slowing down your system. Try putting the original 2gb stick back in see what happens.
 
Yes, it's very possible that RAM could be the problem as well. Uncompatible RAM sticks may cause motherboard to set them to minimum speeds.
 
carl varley said:
It really sounds like it is a problem with the new ram module. It could be slowing down your system. Try putting the original 2gb stick back in see what happens.
Click to expand...

niho said:
Yes, it's very possible that RAM could be the problem as well. Uncompatible RAM sticks may cause motherboard to set them to minimum speeds.
Click to expand...

I put the original RAM back in and still have the same issue.
 
niho said:
I'm no pro,
But if you mess with a thermal controller by mistake, it throttles the CPU. You have to fix the heat sensor cables.
Click to expand...
It was just the LCD heat temp cable. It shouldn't have anything to do with the CPU I don't think. The readings I get all seem normal, the only issue is the fans going full speed without Mac Fan Control but that seems to be a common thing that people work around. Either way, I'm going to try fixing the cable that broke and see if that helps.
 
Last edited:
I'm still thinking it may be something with the SSD. The 27-inch 2010 iMac has three SATA connectors on the logic board. Maybe you plugged it into the slower SATA port that's for the ODD. The Apple Technician Guide would be useful to figure that out.
 
Cookie18 said:
It was just the LCD heat temp cable. It shouldn't have anything to do with the CPU I don't think. The readings I get all seem normal, the only issue is the fans going full speed without Mac Fan Control but that seems to be a common thing that people work around. Either way, I'm going to try fixing the cable that broke and see if that helps.
Click to expand...
You can see if the CPU is boosting to proper speeds using "Intel power gadget". Just run it while using a CPU intensive app like Cinebench.
Also as mentioned above, SSD may be an issue as well, you may need something like "OWC in-Line Digital Thermal Sensor HDD Upgrade Cable"
 
rpmurray said:
I'm still thinking it may be something with the SSD. The 27-inch 2010 iMac has three SATA connectors on the logic board. Maybe you plugged it into the slower SATA port that's for the ODD. The Apple Technician Guide would be useful to figure that out.
Click to expand...
I plugged the SSD into the Sata that the original HDD was using. I have the 2.5" hooked up to the ODD cable via an adapter. If there was an issue with the SSD would it show up on a speed test? I ran one before and I was getting the max speeds for the Sata port.

niho said:
You can see if the CPU is boosting to proper speeds using "Intel power gadget". Just run it while using a CPU intensive app like Cinebench.
Also as mentioned above, SSD may be an issue as well, you may need something like "OWC in-Line Digital Thermal Sensor HDD Upgrade Cable"
Click to expand...
Thank you, I'm going to check this out tomorrow. Although I don't know why it would be causing it I'm kind of leaning towards it being a thermal thing. I'll check with the software first but I'll probably just order the replacement cable.
 
So I just got around to trying to fix this again. I got COVID and it kind of fell by the way side. I tried downloading Intel Power Gadget but the i7 in the 2010 iMac is too old for it to run. It won't let me install it. I also installed istat menu and the CPU is at 37C while doing a Cinebench run so that obviously seems off, it does claim to be running at 100% though. I'm going to try opening it up and replacing the thermal cables to see if that fixes it.
 
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The new LCD Temp cable arrived today so I'm going to be working on this to see if I can get it back to 100%.

So far, I just put the new cable in and while it seems to be registering some temps better than before the fans still blast up to 100% and I'm still seeing the same issue that would suggest the LCD temp sensor isn't the issue. Doing a Cinebench run now.

Edit 1: During the Cinebench run the CPU temp is showing as 37/38C.
 
niho said:
I'd try resetting SMC, PRAM etc.
Click to expand...
I'm going to try that. I just put the original HDD back in with the thermal cables all connected and still have the fans on full blast. Going to run another Cinebench anyway. The last Cinebench didn't improve with the new LCD temp cable.

Narrowing it down some more I think the next thing to check is the CPU temp sensors. Istat is showing no temperature for the CPU heatsink. It's now the only temperature which doesn't display.
 
Potential success!

I'm running a new Cinebench but on this turn on there are no fans and all temperatures are reading correctly. The CPU is currently up to 63C during the Cinebench run and climbing. Much better than the 37C or so that I had before.

This time the only thing I changed was I checked the CPU heatsink. Of course, the heatsink cable was unplugged. I must have missed it when changing the processor. That doesn't explain why I was having the issues before I upgraded the processor though. I'm pretty sure the LCD temp cable would have fixed that issue if I hadn't already upgraded the processor.
 
Complete success!

Cinebench score was 3x higher than before and it seems to be in line with where it should be.

Geekbench score was slightly higher than the average. I've now added back the RAM that I took out incase that was the issue and I'm going to run them again but that seems to be all.

In short, the LCD Temp cable is incredibly important and don't forget to plug the heatsink back in if you upgrade the processor lol.
 
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Happy to hear that it's fixed.yeah, thermal sensors are very important on Macs, for performance and noise management. There is an option to disable thermal management, by modifiying kexts,but it also disables CPU boosting.
And I've seen that you had COVID, also happy to hear that you've recovered.
 
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