Windows 7 Forums
Welcome to Windows 7 Forums. Our forum is dedicated to helping you find support and solutions for any problems regarding your Windows 7 PC be it Dell, HP, Acer, Asus or a custom build. We also provide an extensive Windows 7 tutorial section that covers a wide range of tips and tricks.

Windows 7: exFat Formatting for ReadyBoost

29 Nov 2010   #1

Windows 7 Home Premium (64bit)
exFat Formatting for ReadyBoost

Hello everyone, I've recently been looking into trying to speed up my HP laptop using my Kingston 16GB flashdrive, I am already using ReadyBoost with the drive formatted to the FAT32 file system.

My question: Is it worthwhile to format the drive to exFat in order to allow for more ReadyBoost space? I currently only have 3GB of RAM, which for most things is fine, but I'm currently playing Fallout New Vegas, and the extra 4GBs ReadyBoost provides helps A LOT, so I'd like to get 8 or even 12GB out of my memory stick if possible.

Please help me! Fallout NV runs pretty well but occasionally the FPS drops to an annoying level, I'm hoping that increasing my ReadyBoost to 8 or 12GB it will at least help.

Another thing I'm confused about is while using the format tool within windows explorer it provides an option to pick "Allocation unit size", what exactly does that mean, and should I decide to format to exFAT what would be a preferable unit size?

Thank you oh so much in advance !


My System SpecsSystem Spec
29 Nov 2010   #2

Windows 7 x64 pro/ Windows 7 x86 Pro/ XP SP3 x86

If you choose FAT16 or 32 format you are limited to 4gig, but if you use NTFS or exFAT, it should use the whole thing, as far as I know you can go upto 16 gb with exFAT.

Use exFAT, that'll be the fastest.

Allocation unit size is the Cluster size, it the amount of data that can be read into RAM in a single read instruction, so the bigger it is the better. The flip side is bigger minimum file size so more wasted space, but if you're going to use the drive exclusively for readyboost, try out exFAT with 32 mb allocation unit size.
My System SpecsSystem Spec
29 Nov 2010   #3

Microsoft Community Contributor Award Recipient


Allocation unit (cluster) is a file system measurement unit. When you format your HD in Windows, the default cluster is 4,096 bytes (NTFS). One cluster can have data from one file only.

exFat Formatting for ReadyBoost-cluster_2.png

If you for instance store, save a file that is 40,960 bytes big, it's stored in optimal circumstances in 10 clusters next to each other. Normally HD's fragment a bit, the file is stored in clusters not next to each other. Logically, a file that is stored to clusters next to each other is faster to access, so you have to defragment your HD every now and then. Defragmenting tries to move clusters from one file to next to each other. On the other hand, a very small cluster size means computer has more clusters to seek and search, increasing access time, so access time is not only depending on how fragmented the HD is.

As I mentioned, one cluster can only have data from one file. This means that cluster is reserved even if there is only a byte or two in it. Let's say you save a file that is 5,000 bytes big. It needs two clusters (NTSF default), one to fill it with first 4,096 bytes of that file and the second to put last 904 bytes. Both clusters are now reserved, and you can not save anything else in to these clusters. This is why if you check properties of a file or a folder, you can see two different values, size and size on disk:

exFat Formatting for ReadyBoost-cluster_3.png

This example file for instance is 40,059 bytes, filling 9 clusters full and one partially, so it needs 10 clusters * 4,096 bytes = 40,960 bytes disk space.

In bigger files and / or folders you can regain that "lost space" by compressing files, so the used space can in fact be smaller than the actual size. Here, in my USers folder for instance I've gained over two gigs by compressing some rarely used files:

exFat Formatting for ReadyBoost-cluster_1.png


My System SpecsSystem Spec

29 Nov 2010   #4

Windows 7 Home Premium (64bit)

Thanks so much for the tips, and that big reply about clusters was very informative, way better explained than anything I could find via google

Thanks again, and have yourselves a good day :)
My System SpecsSystem Spec
21 May 2011   #5

Microsoft Windows 7 Professional 64-bit 7601 Multiprocessor Free Service Pack 1

Quote   Quote: Originally Posted by Kari View Post
In bigger files and / or folders you can regain that "lost space" by compressing files, so the used space can in fact be smaller than the actual size.
How does the compression save space? Does it use the unused space in partially filled clusters?
My System SpecsSystem Spec

 exFat Formatting for ReadyBoost

Thread Tools

Similar help and support threads
Thread Forum
Need Help Please with exFAT Drive
I purchase a 500gb exFAT Drive on eBay. I did not think to format to NTFS and I copy family videos to it and then deleted those videos from my PC. All I see is the folders that the videos are in but when I click on the folder it is empty. It should that there is data on the drive but it is only...
Hardware & Devices
exFat Partition??
Hi - I have a Win 8.1 laptop that I'm going to update to Win 10. I was shocked when I looked at my PC and found that 59gb is partitioned as an exFAT partition. Leaving me with a measly 21gb useable on the PC. There are no files written to this partition. Just wondering what the purpose is...
Hardware & Devices
USB drive formatting back to FAT32 after formatting to NTFS
Last night, I tried to transfer a video file as I've done dozens of times. It didn't work. I tried a second time and realized it was because the file was more than 4GB which FAT32 USB drives will not accept. I successfully formatted the new USB drive to NTFS. My question is can I convert it...
Hardware & Devices
Any drawbacks from using exFAT?
Hi everyone, I work with a significantly large amount of files which I store in a 2GB flash drive, and, today, I came across an issue of the FAT format, which is that you can't have more than 161 files/folders in a directory. As the exFAT format is newer, I thought about changing to that one...
Hardware & Devices
exFAT format??
I just built a new machine and want to test my luck with Win 7 on it. The OS HD is a SSD so I am really interested in using the exFAT format. A few of my friends said they were able to format their HD's to exFAT during the Win 7 install but for some reason, while my install allows me to format the...
Installation & Setup

Our Sites

Site Links

About Us

Find Us

Windows 7 Forums is an independent web site and has not been authorized, sponsored, or otherwise approved by Microsoft Corporation. "Windows 7" and related materials are trademarks of Microsoft Corp.

Designer Media Ltd

All times are GMT -5. The time now is 00:09.
Twitter Facebook Google+