Cache for MacAir + external HDD

[John F]

When I need a larger but portable HDD (PhotoShop, OCR) to go with my MacAir, I use an external HDD. This works very well but it is quite slow. Is there a way to configure the available space on the SSD in the MacAir as a cache, but that would be available when I am using the MacAir without the external?

[chas_m]

Not that I know of. Does your MacBook Air have Thunderbolt? If so, I'd suggest a Thunderbolt drive. Speed will not be an issue.

Another alternative: get a hybrid HD. This will perform exactly as you are asking for, giving you almost the full speed of an SSD with the storage capacity and price of an HDD. I am looking at one on Amazon (a Seagate) that is a 1TB 2.5" with 8GB of NAND for $120. Put a portable case on that and I think you're in business.

[rustyk123]

Another alternative: get a hybrid HD. This will perform exactly as you are asking for, giving you almost the full speed of an SSD with the storage capacity and price of an HDD. I am looking at one on Amazon (a Seagate) that is a 1TB 2.5" with 8GB of NAND for $120. Put a portable case on that and I think you're in business.

Good idea, but those would only help internal. The limiting factor is the interface. USB and firewire can only transfer at a limited speed. Thunderbolt helps because the limit is higher then the limit on the drive.

However it is possible depending on the software. Adobe product support this, however unless you changed this setting, then it is already configured to do this. Adobe products by default use your RAM then if it runs out moves to a file on your primary hard drive. Just for kicks try this, hold Shift, Option, Command and launch Photoshop (While holding the keys) once it starts it should come up with message asking if you want to delete the settings file, press yes, this will erase all the temp files photoshop has created but has not deleted for some reason, it might free up a little space and help a little bit.

[John F]

I tried it anyway - added a Hybrid 1TB HDD / 64MB cache in an external enclosure to my 11" Mac Air. The performance improvement is startling. The USB is still slow, but adding slow to slow makes very very slow, and having an HDD/cache that speeds things up a lot makes a huge difference even if it is external. I still wouldn't want to use it to edit a long movie or mix an orchestral concert, but Photoshop and YouTube clips are going to be a snap. Some tasks are still naturally slow, but much of the time it is subjectively as fast as when booted from the internal SSD.

[John F]

Since my last comment I have upgraded my external HDD to a 500GB SSD. Still the portability of the 11" MacAir with the utility of a much larger computer and very usable speed. I would recommend it highly to anyone who travels a lot.