Do firmware updates affect print speeds?

Question

I flashed the TH3D unified firmware (R2.7) yesterday and so far everything works. I printed the 20 mm cube using the same G-code file I used for my very first print ever. However, with TH3D firmware I noticed that the print head was ridiculously fast compared to the previous firmware. The new cube has layer shifting and more noticeable ghosting so I know it's not just my imagination/faulty memory.

The slicer should have everything moving at 60 mm/s but I feel like the printer is going like 80+ mm/s. I only uncommented my printer model and a couple of features of the firmware; nothing involving speed (mainly the mesh bed leveling). Is it possible that the new firmware thinks 60 mm/s is a different speed than the original?

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^{Note: This question isn't about print quality. While the cube had flaws, it was just testing that the printer would actually print. And, of course, I can just dial things down. This question's scope is just about the input of the G-code and the output of an actual speed of printer head facilitated by the firmware.}

Answer 1

I agree with @silver, but also wanted to point out that maybe the acceleration values on the old firmware you had were different from the default in TH3D R2.7.

The current settings can be retrieved using the M503 command, which should return the values from the eeprom:

Maximum Acceleration (units/s2):
M201 X1000 Y1000 Z100 E10000
Acceleration (units/s2): P R T
M204 P400.00 R1000.00 T1000.00

You can then lookup the default settings for your printer model and use M201 and M204 to set the new values. Then M500 to save the new settings to the EEPROM.

Answer 2

Yes, the limits are often subject to some "interpretation" in the limiting algorithms, even if they are totally unchanged values. Eg, your speed may remain higher around corners if the momentum calculations were optimized to take into account print head weight and extrusion instead of only per axis speed curves.