Hey man, I'm sorry.. but no.

Formatting as FAT will have no difference to FAT32. FAT is, in fact, the default filesystem for ALL removable drives in XP. What makes it smaller is the cluster size. But it isn't a promise. Here goes my attempt at a quick explaination.

The FAT filesystem (as well as NTFS, but that's irrelevant) stores files in what are called clusters. Each cluster has a specific size, and an address. When a certain file is needed and/or loaded, it is checked where it is with the address, loads the first cluster, then if the next cluster isn't right after it (this is known as FRAGMENTATION), it will go back to find the next address, and so on. The size of a cluster can vary, and you can customize it even (within reason) depending on the size of the drive. If a cluster size for a particular drive is, say, 8KB, then that means that EVERY single file on the drive will consume space in a multiple of 8KB. So yes, even if a file is LESS THAN 1KB, it will consume 8KB. If a file is 17KB, it will consume 24KB. So on, and so forth. This may not seem like much, but it can add up - especially if you have lots of small files on your MSDuo, from homebrew like iRShell for example.

So, having a SMALLER cluster size can save a lot of space (comparitively speaking). So i can see you asking - "Why don't wee use the smallest cluster size ALWAYS (which is 512 bytes, or half of a kilobyte/KB)?" Two reasons. 1: Depending on the size of the volume, you cannot physically have a cluster size that low. With my 2GB MSDuo on FAT/FAT16, the lowest cluster size i can have is 32KB. On FAT32, it's 2KB (or maybe 1KB, or 4KB... sorry!). And, 2: Having a lower cluster size MAY SAVE SPACE, but it can DESTROY access times, resulting in an extrmely slow PSP XMB and gaming experience. This is because whenever a file or piece of data is loaded, it has to find the address of the cluster. Once it reads that 8KB chunk of data (if the cluster size is 8KB for example), it has to go back to the file-system's header (called the MFT on FAT12/16/32 i think, or is that NTFS), find the address for the cluster that has the next bit of data, then go back and load that. This process is ongoing and continuous for every FAT(16), FAT32 and NTFS file system. THIS is why defragmentation on your computer is important for speed! If the data is contigious (contingious?) (this means that ALL clusters for one file are placed exactly one after the other), then it doesn't NEED to check the MFT! On a PC HDD which is mechanical in nature, this is VITAL to speed and extendng your computer's life! Fragmentation, which also happens on PSP MSDuo's (but provides a debatable amount of performance boost); increases loading times, CPU and/or disk controller workload, and especially in the case of a mechanical drive (a computer harddisk), REDUCES LIFE EXPECTANCY. THESE LISTED SIDE EFFECTS OF FRAGMENTATION APPLY ONE HUNDRED PERCENT TO A SMALLER CLUSTER SIZE. But it is not as extreme.

Confusing, no? Consider these facts. The tests are performed on my MSDuo Pro 2GB (marked as Sony, but i think it's a knock-off fake). "FAT" in Windows is actually FAT16 by the way.

FAT16 FS, 32KB CLUSTER SIZE:
- Filesystem used when formating within the PSP's XMB
- Fastest game loading, music playing, video seeking performance compared to any other configuration I am listing here.
- Not too efficient on space, especially with iRShell installed.

FAT16 cannot support a cluster size lower than 32KB on a 2GB drive. (SOMEONE CONFIRM ME ON THIS. I AM NOT HOME SO Don't HAVE MY PSP TO TEST, BUT I'M PRETTY SURE I COULDNT FORMAT TO 16KB.) Time for FAT32.

FAT32 FS, *KB CLUSTER SIZE:
- MY PERSONAL recommended configuration for a 2GB stick.
- Speeds of game loading and seeking in AVC video's were a bit slower, but hardly noticible. Worth it for the space.
- Recommended to everyone with a 2GB stick and a 2.71+ FW (as firmware below only supports FAT16 im pretty sure, i know that 1.50 wouldnt support FAT32 anyway)

FAT32 FS, 2KB CLUSTER SIZE:
- The lowest cluster size i could format to (I THINK, doesn't really matter if it was 4KB or 1KB all the info to follow is STILL VERY VALID).
- .......this is f*****g horrible. As soon as i formatted, copied everything back to my MSDuo and closed USB connection, I could notice the slow down when browsing the XMB. I straight away went to MSDuo under music, and "Free Space" was simply "-". No number, just a dash. The MSDuo access LED would flick on every few seconds, and finally, after 15 seconds or so, the free space figure of 1072MB appeared. Upon entering my music, it was a nightmare. After 5 seconds, the title for the first song appeared. After 7, the next. Right. I'm not even going to bother telling you how long it took me to load a title screen in an ISO! Obiously the PSP could not keep up with the constant
seeking-back-and-forth between the MFT and cluster addresses. I did defragment the MSDuo and up the XMB clock to 333, but the speed increase was not worth the decreased battery life and the hassle of defraging all the time.

Sorry for the length. I may update this if anyone cares, or make a new post with a guide/screenshots and such. But how many people already actually know this? I'm assuming quite a few as you guys seem pretty PC-savvy.

Hope someone found that enlightening. Feel free to challenge my notes if you like! Peace.

NOTE: I have listed *KB as the cluster size for my personal favorite as i cannot remember what it is. I think i use 8KB FAT32, but it might be 16KB. I could check if anyone cares to know.

NOTE2: Smaller cluster sizes generally become fragmented quicker than a drive of larger cluster sizes. Larger cluster sized drives are also FASTER in seeking data. This is why I have a 2GB partition of cluster size 64KB, at the beginning of my second drive for my SWAP file in Vista :)Sorry for double post. I have a valid reason though, i think (1 is answering a quote, 2 is too huge to stuff it together)

Ge64 Wrote:doesn't it have to do something with cluster size? if you have large files you're better off with large clusters (for speed), but small files take up a whole cluster so if you have lots of small files you need a small cluster size, because a file takes up at least 1 cluster, not half a cluster.
so if you have 4kb clusters and you have a 50 byte file, it will say 'size on disk: 4kb'.

but i don't think you can change cluster sizes on a memory stick, can you ?

You can format any drive in 2K/XP/Vista command prompt with a specific cluster size and/or filesystem.

WARNING: DO NOT ATTEMPT THIS IF YOU ARE A NEWBIE AT PC STUFF. I WILL NOT BE HELP RESPONISBLE IF YOU DESTROY, DAMAGE, OR LOOSE ANYTHING.


1: Start > Run > Type in "cmd" without the two " and hit enter
2: type in "FORMAT /?" to show the format tool with all available help.
3: Quick help if u couldnt be stuffed:
      FORMAT [DRIVE LETTER] /FS:[FILESYSTEM] /A:[CLUSTER SIZE]
      Example - to format my PSP on drive P:, in FAT32, with a cluster size of 16KB...
              FORMAT P: /FS:FAT32 /A:16K


LEGEND
   [DRIVE LETTER]
      The drive letter with a trailing : of your PSP connected over USB (in XMB). Example, F:
   [FILESYSTEM]
      Can be either FAT for FAT16, FAT32 for FAT32, or NTFS. NTFS is incompatible with the PSP.
   [CLUSTER SIZE]
      Can be either 512, 1024, 2048, 4096, 8192, 16K, 32K or 64K.
      LOWER CLUSTER SIZE=MORE EFFICIENT SPACE, SLOWER PSP, HIGHER FRAGMENTATION RATES, LOWER LIFE EXPECTANCY
      HIGHER CLUSTER SIZE=LESS EFFICIENT SPACE, FASTER PSP, LOWER RATE OF FRAGMENTATION, HIGHER LIFE EXPECTANCY.


There are partition tools that can change cluster sizes WITHOUT formatting, but i highly recommend against those. Just copy all ur files off MSDuo > PC, format P: /blahblah, then copy files from PC > MSDuo. U don't need to format the MSDuo in the XMB to get it to work, just as long as you copy your ENTIRE MSDuo to PC you will be fine.