Can lack of a battery slow down your Mac Pro computer dramatically?


One always expects that a wall socket can deliver more electrical current and power than a battery. Thus, not unreasonable to think that your Mac Pro should run faster when connected to the wall charger, even if its battery is removed. However, reality is different as we recently learnt with Meghafind  Scouts.

In a simple experiment, when our Mac Pro’s battery was slowly dying and needed a replacement, we measured this laptop’s performance in 3 conditions. First, with the old battery and connected to the wall charger. Then with the battery removed but Mac working on wall power alone, and lastly with the new battery installed and the wall charger also plugged in. Meghafind Scouts measure the CPU, Memory and Storage scores with faster run-times representing a faster machine. Lower the numbers better it is.

Results were so startling so we had to write this blog to share them.

Figure 1: A Mac Pro running on wall-power alone can be 3X slower.

So how can this be explained? Without any access to internal power supply secrets of a Mac, that Apple surely wants to hide and protect, it is safe to assume that the Mac Pro needs more current than its wall power charger can provide. Thus, a part of the charge comes from the battery even when connected to the wall. This is reasonable, as performance improved when a new battery was put in, but most surprisingly, Mac’s performance was up to 3X slower when on the wall power charger alone. Wonder if other PC manufacturers do it the same way? There is only one good way to find out, by using Meghafind Scouts.