augiealexander

LOL... that must be sarcasm. Had I owned that original disk I probably would have tried that first. But I was too lazy, cheap, and especially impatient to wait for it to become available. it is going to be nice knowing it's a super fresh install. No fat. A lean mean machine.

!!!!!!! [sOLVED] !!!!!!!! I’m so relieved and excited to have found the solution. My testing included 4 MacBook Pros, and 4 iMac’s, all 2011 and a little variety between them in respect to Processor Speed, Hard Drive upgrades, etc. My Master Boot Drive was created on an Early 2011 MBP by starting with the Original Install Discs, internet update from 10.6.6 to 10.6.8, and then installation from disc images of Logic Pro Studio 9, Waves 8, NI Komplete, Sound Toys 4.3.3, Slate Trigger, Addictive Drums, Altiverb, Pod Farm Platinum 2.5.9 and a few other things. This Master Drive was Cloned and appeared to work perfectly across all 2011 machines or older. However, when running on the 2011 iMac i5 or i7 , their processor was only working at 50% the Geekbench mark average. Strangely enough - the iMAC processors worked normal with clones of Lion, Mountain Lion, El Capitan, Sierra & High Sierra. Something about Snow Leopard was not compatible… But these machines SHIPPED with Snow Leopard. My tests were extensive and detailed. I bought the original OS X Install discs for the 2011 iMac from ebay and they arrived yesterday. Sure enough, I erased the Hard Drive and reinstalled the OS X from scratch on an iMAC. As you all may know, Apple made it very difficult to install the native software directly thru the machine unless you have the original install disk. That’s one reason I used the clone. I have now completed fresh installations on two 3.4GHz 2011 iMac’s, one with the original 7200 drive and another with a Mercury Extreme Pro drive. Both are measuring over the Geekbench average and running my trusted software with EASE. And when the GPU goes down… no problem, I have another machine ready to go. And then another. Thank you to Mr. T for the moral support and ideas.

Nope. I have a computer for Non-Music stuff. For music, I'll switch to Logic X when I'm ready. For now, I have some great sessions going in Logic 9. I've had some life events that set me back here and there, but I got up and I'm going to get across that finish line. I have working machines for these projects, but while this issue is fresh in my head, I want to solve it.

I appreciate you. I guess we will see. I'm running out of options. I have 4 iMac's now, but only one with an original Apple drive. I'm waiting for the original install discs via eBay. All four machines work fine in High Sierra. The few I tested in Lion also work fine. It's not until I copy my MBP version of Snow Leopard and they slow down. This MBP version works fine across all the MBP's. Again, None of the 4 iMac's are working properly with Snow Leopard, not even a fresh install clone. But all 4 machines work fine in High Sierra. Isn't that weird? how could I have 4 iMAC's all with a weird hardware issue?

High Sierra seems to work perfectly on the iMAC's. No CPU issues. In Fact, Lion, Mountain Lion, Mavericks, Yosemite, El Capitan, Sierra, and High Sierra all work fine. Geekbench is giving me in-line scores even on the 2011 machines. The only issue is with Snow Leopard, even though these machines shipped with Snow Leopard, which is super weird. Leads me to think it recognize a user trying to inject Snow leopard w/o going thru the proper channels. It could actually be a security feature that was in place at the time. Meaning, it's behaving normal. They are pretty clear about how we're allowed to use there OS, and not forgiving to anyone that crosses that line.

UPDATE: I’m feeling very strongly this is either a software or firmware issue. At this time, I only have the original install discs for 2011 15” MacBook Pros. This is what I used to make the master, and all other drives a clone of this one. This Snow Leopard Clone will boot and appear to work normally in all of my 2011, 2010, 2009 machines I( MBP, MAC PROS, and iMac’s). I can either manually install the hard drive or install by setting a machine in Target Disk Mode. What I think I discovered is on the iMac in particular, although this Clone boots perfectly, the CPU is not running at full capacity (Geekbench 3 report). Hypothesis #1 is that the iMAC recognizes the Clone is an imposter and will only run correctly when starting with it’s own factory version of 10.6.6 (Grey Face Disk) and then updated accordingly. This might also be true for the MAC PRO’s and maybe the reverse if trying to run an Clone from an iMAC on the notebook. Hypothesis #2 is that when people updated to High Sierra on these 2011 machines, there was a firmware update that is throttling the CPU when trying to revert to Snow Leopard. I have a couple MBP’s that were upgraded to High Sierra and I was able to revert using the clone, so it it is a firmware issue, it’s only on the iMACs…. I also have a line 2009 17” that is also throttling when the clone is installed. On macOS from Lion and above, when running Geekbench 3,4 & 5 work as expected. No CPU issues reported. This of course is only a handful of tests, but so far it’s consistent. The only issue is when trying to us my Snow Leopard Clone made from a 2011 MBP in a non MBP machine. I am now waiting for the original factory OS X install discs I won on ebay. When trying to do an Internet Recovery on these machines that were shipped with Snow Leopard, aple will only allow me to install Lion.

UPDATE: I have found more support leading me to believe replacing the original hard drive is the issue. I ordered a couple used HDD's that are supposed to be factory originals for the 3.4GHZ i7's that are running slow..... in the meantime, I just remembered my son has an old iMAC that someone handed down to him, and that someone wouldn't have upgraded. I was in luck to find it's also a MID-2011, but the i5 2.5GHZ. I ran the geekbench score on it and it scored even higher than the Geekbench posted averages. Unbelievable. So many people have been replacing their HDD with a SSD at cutting their processing time in half. We don't know how systemic this is, or if it's only a result of improper upgrades, or accidents in the process, or something of that nature. I'm now wondering if the cable with the thermal sensor that macsales or ifixit provides actually does the trick. Or does upgrading to a SSD just make your mac appear to be zippy, while actual processing is handicapped. These models even have a third SATA connection in addition to the HDD and the ODD. I think I might try restoring the original factory HDD in it's normal spot for thermal sensing stability, and then make that second one my boot drive to see what results I get. I love this Forum. I usually never post because I'm always able to find the answer. Thanks Mr. Triplets. I tried real hard to ignore that it might be the HDD. I'll be back in a few weeks for what I hope to be a final update.

Thanks Infirium, My mistake, it was the ambient temperature sensor they were talking about. One of these two iMAC's I have does have something up with one of the fans, the other one all three fans seem normal, but this is a great place to investigate further... if temperature sensors are known to cause the CPU to throttle down, that could be the problem.

Mr. triplets, I think I see where you were going with the original factory HD suggestion. I stormed the world wide web and my issue might not necessarily be HD in nature, but thermal sensor, which the factory HD has a very specific one. I found one post on ifixit where apparently there is a common mistake when putting machines back together after SSD upgrades where the LCD thermal sensor's are replaced upside down, and the iMAC has a mechanism in place to intentionally slow down the processor if the thermal sensors aren't working correctly. This should have come up in my Hardware Test. But who knows. That's my next stop and I'll keep you posted.

Ahhhh, I found this... CPUs get slower over time because of dust build-up on the heatsink, and because the lower-quality thermal paste that prebuilt computers are often shipped with will degrade or evaporate. These effects cause the CPU to overheat, at which point it will throttle its speed to prevent damage. I just did the thermal paste thing trying to resurrect the MBP. I'm going to check this out. Might take a few days to get to it.

I see, Yes. Both MBP's also have the upgraded drives and it didn't cause any problems, only enhancements. So I assumed the same would apply to the iMAC. Before I started tracking details, I did try to use the first iMAC As-Is and it fell way short. I assumed it was because of both the boot drive not matching the MBP as well as the session drive being connected in the optical slot, as opposed to FW800. When I found out how intense the upgrade was on the iMAC, I put that project off for two years, afraid to climb under the hood. Recently one of my MBP's fell victim to Radeongate (GPU failure), which inspired me to upgrade the iMAC. It was easier than I thought, but still took a long time because I didn't want to ruin it.

I can't easily test the factory HD. I believe I do have one of the factory 3.5" drives that I personally replaced with a SSD. The geekbench report seems to focus on the processing. The HD and Memory specs all check out. Something is happening with the processor. I understand that I don't know what I don't know and it could still be a HD issue.

Both iMAC's I have are the same model as I plugged into the everymac.com link to compare specs in my first post above. iMAC 27-inch MID 2011. Both MBP's are coming up on my Geekbench 3 in line with what is reported at everymac.com Geekbench, but both iMACs are coming in at around half of what is reported. So weird. Makes me think it's a software thing that's slowing them down... or maybe a firmware update the previous owners may have installed to upgrade. or something in that neighborhood. The geekbench app has a six page report. Other than comparing the SC and MC numbers, it's all Greek to me.

I now have two identical 3.4GHz iMACs testing against two 2.xGHz MBP's. I bought Geekbench 3 and ran tests. I guess we can rule our LOGIC as an issue, and I'm in the wrong forum. Check out these results: Both iMACs scored around 1425 and 5440 in single-Core and Multi-Core. Both MBPs scored around 2575 and 9825 in single-Core and Multi-Core. If anyone has a suggestion as to where I should go to help solve this, please LMK.

Thanks for sticking with me. I love this forum because I have learned from you guys how to completely optimize my system. I am running all the tests from a blank audio track with no plugs, info, instruments. This iMAC seems to be in incredible shape inside and out. I know that dosen't mean it's issue free. I'm setting up a second iMAC with same specs now. Hopefully done by tonight.