Is there a spec difference between the PS3 slim models?

Is there any difference between, for example, a 160GB model and a 320GB model aside from the HDD size? Does any model have newer, more powerful components?

Wikipedia suggests that there isn't a difference, however I'd like to be sure.

Solution 1:

Not all PS3 Slim models are identical. There are some minor and major (depending on your use case) differences between the different Slim modes.

HDD Size

Not all models have the same Hard Drive size from the factory. As they are standard 2.5' SATA drives, you can change this size at any time so is not that important.

This are the different sizes that come in the different PS3 models:

CECH-20XXA and CECH-21XXA consoles have 120GB drives
CECH-25XXA and CECH-30XXA consoles have 160GB drives
CECH-20XXB and CECH-21XXB consoles have 250GB drives
CECH-25XXB and CECH-30XXB consoles have 320GB drives

Custom Firmware Support

Not all PS3 models can run Custom Firmware, or CFW. Custom Firmware are special operating system versions for the PS3 that allow you to do stuff similar to the Development Consoles that Sony sells to developers.

All of the CECH-20XX and CECH-21XX consoles can run Custom Firmware, while some CECH-25XX consoles with a Datecode (manufacturing date) of 1A and 1B can. None of the CECH-30XX consoles can run CFW.

Energy efficiency

The CECH-20XX models have the Reality Synthesizer (RSX) chip made in an older process node, which means that they are less efficient than the CECH-21XX, CECH-25XX and CECH-30XX consoles.

The CECH-20XX consoles have RSX Chips made in the 65nm process, while all other models released after that have RSX Chips made in the 40nm process (and some Super Slim models in 28nm).

Solution 2:

All slim models are identical. Only the HDD capacity will vary.
You can have the list of models here.