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I noticed we can set two hard drives or more for virtual memory page file. But my guess is, if it is the same hard drive, just two different partitions, then it may as well be just one partition? (we don't want the hard drive's head to move across back and forth the two partitions)?

If I use two hard drives... one internal and one external, then the external hard drive on USB 2.0 might not help much either, as the transfer rate is only about 30MB/s... maybe another internal hard drive will help, or another hard drive on USB 3.0 might help, which I don't have right now, so it probably won't help?

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Your suspicions are correct: Putting 2 page files on two different partitions on the same physical drive decreases performance because of the additional large seeks involved.

I'm not sure if Windows will let you put a page file on a USB drive, but USB 2.0 would be far too slow.

One page file per physical drive is best for performance, and Windows Vista and newer do this automatically by default, and 2000 and XP can be configured for it.

All this said, I'd you're doing enough swapping that you're worried about these kind of performance effects, then more RAM is going to be a much, much better remedy than even using a high end SSD for page file storage.

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Windows will not let you put a pagefile on a USB drive, or any other drive it thinks is removable. – Jamie Hanrahan Jan 25 at 13:17

It can sometimes be helpful to move the pagefile to a different partition for space reasons, but not for speed reasons.

Having the pagefile on a different disk to where the majority of your disk activity is happening is ideal. As you expect, you want fast transfer from the page file to memory, so anything you can do to reduce bottlenecks will help.

Adding more RAM is ultimately the best way to reduce performance issues related to pagefile swaps.

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I can't help but agree with your reasoning. Separate internal or USB 3 drives are the way to go. (FYI, I was wondering about latency/random IO performance over USB3 but it seems fine - it seems SSDs can achive +20MB/sec random 4k over USB3, so no worries there with a HDD).

Of course, the proper ways to deal with pagefile issues is to get more RAM and/or put it on a SSD.

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