2019 iMac 27 inch base model CPU speed

[Spectrum]

We just took delivery of the base 2019 iMac. Specs are 3.0 Ghz, with single core turbo to 4.1 (6-core turbo of 3.9 Ghz).

There are lots of reports about how the i9 version can't manage all-core turbo due to design limitations of the case and/or power supply. So I though it interesting to see how the i5 base model compares:

Running a "yes > /dev/null &" test, which pegs all 6 cores at 100%, leads to a stable 3.9 Ghz, 92C, with the fans not audible.

This is well above the base speed, and exactly in line with the expected max turbo for 6 cores. I think that is mighty impressive.

Has anyone run a similar test on the top-spec (3.7 Ghz) 2019 iMac?

 

[azentropy]

Was attempting to run some tests for you on my new 8-Core i9. However trying to install Intel Power Gadget hung my system on reboot. Had to remove manually booting from another drive as even safe mode wouldn't work. Seem so to have an issue with Catalina.

 

[Spectrum]

Was attempting to run some tests for you on my new 8-Core i9. However trying to install Intel Power Gadget hung my system on reboot. Had to remove manually booting from another drive as even safe mode wouldn't work. Seem so to have an issue with Catalina.

That's a shame - Thanks for trying it out! I guess intel needs to supply an updated version. Do you have a Mojave external boot volume?

Reports suggest that the i9 will max out 8 threads at around 4.5gHz. It would be interesting to see what the 6-thread max speed is!

 

[tyc0746]

Intel Power Gadget works on my 21.5” (6 core i7) on Catalina.

Results are stable 4.4ghz @ 97°C, but the fans were audible (5 instances of terminal with ‘yes > /dev/null”) and Intel Power Gadget using the final core.

 

[Spectrum]

Intel Power Gadget works on my 21.5” (6 core i7) on Catalina.

Results are stable 4.4ghz @ 97°C, but the fans were audible (5 instances of terminal with ‘yes > /dev/null”) and Intel Power Gadget using the final core.

What if you launch 6 instances? The CPU is the same as my Mac mini, so I'm interested to see what is the stable CPU speed of the iMac under 6 core full load Compared to the i7 Mac mini. 👍

 

[Spectrum]

With 5 cores loaded, the best the i7 mac mini can maintain is ~4.2 Gh.
Therefore clearly thermally constrained (-5%) relative to the 21 inch iMac.