On the Mac : Windows, VMs and Flash Drives

If you do not prefer the Bootcamp approach describe in my other article, obviously you can just run Fusion or Parallels and have a virtual Windows environment running alongside your Mac. But again, due to the precious disk space on some Airs, carving out this 20GB to run a VM might not be something you can afford. In reality, this article also applies to Windows laptop with a similarly sized SSD on board. If you have such a machine and just need another Windows VM for testing, continue reading.

Now, there are obvious workarounds to this problem. You can, for example, run it on an SD card or run it on a thumb drive or external portable disks. If you can use an external portable disk, it'll be the most economical way. Read my other article about them. There's one problem with running it off an external disk. It's not exactly very portable since you have to move around with the drive attached to your Air (or laptop). It works, but there's this caveat. If you're going to be sitting on your desk while running the VM, then I think this approach works well. It's not going to be very high performing, but it's reasonable. I do have a few test VMs running off 'Desktop' class external disks.

I've hunted for some time since getting the Air, for a thumb drive/SD card that is reasonably fast so that I can just stick it to the USB port (or SD slot) and carry it around with me. SD card never works, period. They are just too slow. I must admit that I haven't really tried many of them, but I don't really want to waste any more money. The seriously fast ones (as claimed by Sandisk) cost multiple dollars per GB. Unless Sandisk wants to send me one to play with, I'm not going to outright buy them and pray that it works. For the record, I tried a Sony Class 10 and an HP Class 10. Both are 32GB, and both never complete the Windows installation after 1 hour, as far as I can remember.

So I'm left with thumb drives. I had a SanDisk Ultra 64 GB USB Flash Drive SDCZ45-064G-U46 at that time and I decided to try it. It's ok, but still slow. I didn't wait for the Windows installation to complete. I ended up putting Diablo III client on that thumb drive. Yes, that works reasonably but you can get killed due to disk read latency. I know I did a few times. At this point, I realized what I need is something which performs well for small I/O read/write. And it just happens that SanDisk announced their latest thumb drive, the SanDisk Extreme 64 GB USB 3.0 Flash Drive up to 190 MB/s SDCZ80-064G-X46. This is an interesting drive. It sports an USB3 connection and some insane claimed transfer speed. And the best part? It costs about SGD1.4/GB locally here.

I began trawling the web for benchmarks. I found exactly 1 (I can't remember the site, sorry, but it compares this drive with a ton of others). Remember this is more than a year back (probably towards the end of 2012) and USB3 drives with real performance isn't that common place. Most USB3 drives at that time are just their standard USB2 parts retrofitted with an USB3 port. I knew this drive is going to be the one when I saw the benchmarks. The CDM 4K readings are unheard of. They read close to 10MB/s write with the default 4K test. You just have to trust my word as I don't have the URL anymore. Just for comparison sake, almost all flash drive at that time managed barely 1MB/s read/write on the default 4K CDM test.

I took the leap of faith and buy the 64GB version. I popped it into the Air's USB2 ports, format it to HFS+ and straight away put a Fusion VM on it running Windows 7. The speed is incredible, even on an USB2 port. It feels faster than those VMs running off normal external disks. I've been running my primary Windows VM on this drive since. After a year of hard hammering, it's getting slower and slower. I've yet to research this. You can start to feel the momentarily freeze at times, Outlook is not as responsive opening a cached Inbox etc. I'm not exactly sure why this is happening at this point. However, that said, it's still plenty fast mind you.

Even though I'm extremely happy with the purchase, there's a few things I ought to mention.

• This drive is expensive! Price is relative when I said it cost SGD1.4/GB. The other 'normal' flash drives cost like SGD0.80/GB. Price is lower now compared to a year ago.
• If you need to just copy huge files back and forth, you might want to look elsewhere. This guy doesn't score number 1 in sequential transfer. Nor is it the most cost effective for bulk storage.
• This drive shines only if you have a workload which requires small random read/write IO. Running VMs off it is one example.

If you skip all the post and come straight here, I'll say just buy this guy to run VMs off it. You won't go wrong.