The Vista ReadyBoost compatibility list received its 200th submission today.  The list now tracks the ReadyBoost ‘readiness’ of devices from over 45 manufacturers. 

Some fun facts based on the data gathered so far:

• A little over half all tested devices (55%) were confirmed compatible with ReadyBoost.
   
• The highest number of compatible device reports have come from SanDisk users – nearly 20% of all positive reports received.  In total, over 78% of the SanDisk devices were ReadyBoost compatible.
   
• PNY users reported the greatest number of incompatible devices – 12% of all the incompatible devices reported. Most PNY users (55%) found their devices to be incompatible.  Funny then that PNY should choose to mention ReadyBoost as a reason to buy PNY.

If there’s one thing the list does show, it’s that no one manufacturer has ReadyBoost compatibility nailed across their range.  If you’re thinking about buying a new Flash device for ReadyBoost, check the list first.

Finally, many thanks to everyone who have submitted their results so far.  And special thanks to Maverick, Jim Byram and the others who have returned several times with compatibility reports for new Flash devices.  The list wouldn’t exist without all your help.

I recently ordered a Kingston DataTraveler Elite USB Flash drive to try out Vista’s ReadyBoost feature (previously blogged about here).  It arrived in the post from eBuyer today and I decided to run a few semi-scientific tests to see what difference, if any, it made.

Boot Times

I timed Windows startup from cold before and after adding the ReadyBoost device.  I started the timer from the second I pressed the power button, as I wanted to include any time lost through BIOS recognition of the USB device.  The timer was stopped when Vista reached the ‘select user’ screen. 

Before: 49.5 secs
After: 51.0 secs (yep, slower)

This slowdown seemed to be 100% down to device recognition time – it spent a bit longer on the initial BIOS screens, and there wasn’t any noticeable improvement in the rest of the boot process.

Adobe Photoshop startup times

Photoshop is always slow to start, especially if you have lots of filters, fonts and extensions installed.  However, even with regular Windows disk caching it’s much faster to start the second time around.  So for this test I’m timing both start and re-start times for Photoshop.  

Before ReadyBoost, first start: 26.5 secs.  Second start: 14.6 secs.
After ReadyBoost, first start: 16.0 secs.  Second start: 11.7 secs.

That’s much more like it!  The promise of ReadyBoost – that it will significantly speed up access for small files – seems to be proven here.  Photoshop requires access to hundreds, perhaps thousands of small files when starting up.   From listening to the HDD it certainly seems to be doing less work, and the application start times have reduced by 40%…. result!

iTunes startup times

I knew Photoshop was going to be an extreme case (like most Adobe apps) so to balance things out I thought I’d try iTunes too.  With a massive music library, iTunes takes several seconds to start up, so it’s a reasonable one to test (unlike, for example, Word which starts so fast that startup times are difficult to judge).

Before ReadyBoost, first start: 8.2 secs.  Second start: 6.8 secs.
After ReadyBoost, first start: 9.0 secs.  Second start: 6.3 secs.

It’s likely that iTunes startup times were influenced by external factors here, rather than ReadyBoost making things slower.  However, I don’t think ReadyBoost will improve startup times for an app like iTunes either.

Conclusion

As Tom Archer blogged previously on MSDN, ReadyBoost is all about speeding access to small, random file requests.  When you’re doing that (e.g. starting an app that requires lots of tiny files) then ReadyBoost makes a significant improvement – at least 40% faster in my tests.  For that alone, it makes it worth the investment in a fast USB Flash drive. 

The only difficulty is finding the right drive!  My Kingston DataTraveler Elite 1GB seems fine, but previous devices I’ve tried (e.g. Maxell 512MB, Kaser, etc) weren’t fast enough to register for ReadyBoost.  If you’re in any doubt, please check out my ReadyBoost compatibility chart.

ReadyBoost is a new feature of Windows Vista which uses flash memory on a USB drive to boost system performance.  It uses the USB drive as a hard disk cache and/or virtual memory store to speed up file access and increase the apparent RAM available. 

Many people have asked on forums how this could possibly be effective – after all, flash memory has a much slower data transfer rate than most hard disks.  That’s true, but the trick is that good flash memory has a much lower seek time than a hard disk.  By placing many small files on the USB drive, Windows can randomly access these files much more quickly than is normally possible from a hard disk.

The key point is that the USB drive must have very fast seek times.  Many USB flash memory devices, even those with high data transfer rates, don’t have sufficiently fast seek times to make them useful for ReadyBoost.  Unfortunately, manufacturers don’t normally publish random seek times for flash memory like they do for hard disks.  This makes shopping for a ReadyBoost compatible flash drive a bit of a lottery.

It’s possible to force Windows to accept any device for ReadyBoost use via a registry hack.  However, this is not recommended, as the high latency will reduce system performance rather than improve it.

I searched everywhere for a definitive source of ReadyBoost compatible devices, but I couldn’t find one.  So I decided to start one of my own.  You can access it here: ReadyBoost Compatibilty Chart

If you’re currently using Vista and have tried ReadyBoost with your device, please submit your results here.

Comments are welcome!