Hi guys, I am messing around with overclocking a T4 and managed to get it to pass CoreMark at up to 1.08GHz.
Disclamer: I did this at work where we make high performance coldplates.
I used a 10x10mm coldplate and clamped it to the Teensy with some thermal grease. The processor was also milled down about 0.009" so it would be nice and flat.
The coldplate is plumbed up to a faucet and cold tap water is used as coolant.
I ran defragster's code posted in this thread, so far it is at 120 loops (still going at the time of posting this):
Code:
2K performance run parameters for coremark.
CoreMark Size : 666
Total ticks : 14407
Total time (secs): 14.41
Iterations/Sec : 4164.64
Iterations : 60000
Compiler version : GCC5.4.1 20160919 (release) [ARM/embedded-5-branch revision 240496]
Compiler flags : (flags unknown)
Memory location : STACK
seedcrc : 0xE9F5
[0]crclist : 0xE714
[0]crcmatrix : 0x1FD7
[0]crcstate : 0x8E3A
[0]crcfinal : 0xBD59
Correct operation validated. See README.md for run and reporting rules.
CoreMark 1.0 : 4164.64 / GCC5.4.1 20160919 (release) [ARM/embedded-5-branch revision 240496] (flags unknown) / STACK
F_CPU=1080000000 deg C=25 Pass#120
The processor seems to be very sensitive to temperature-
First starting up the system the reported temperature was around 28C and the Teensy was not even able to complete the first loop at this speed.
After letting the faucet run for a few minutes to clear out the "warm" water in the buildings plumbing, the temperature had dropped to 25C and the Teensy seems to have no issue running at this speed.
I' be curious to see a temperature plot while it is actually running CoreMark.
The next clock speed increment, 1.092GHz, would not get through the first CoreMark loop with this setup.
View attachment 30319