GIMP: TEMP Folder should be where?

Hi,

I've noted that my GIMP Portable has been running awfully slow on relatively good computers (2GHz, 1 GB of RAM) when working with only 2000x3000 px images, which is surprising for me. I checked the temporary folder, and it's directed to a location on the flash drive. While this makes a bit of sense, the drive is only 512MB, and USB 2.0 can't transfer that much information that quickly.

So I'm wondering where to direct the temp folder to, especially since I don't know what computer I will be using---and since I will be using both Macs and PCs. Currently my personal computer is a PC.

Any help would be appreciated.

Thanks,
Sam Bloom