To ReadyBoost or not to ReadyBoost?

TLDR, not recommended.

ReadyBoost (and any other kind of disk caching solution) works by creating an intermediate buffer between the fast RAM and slow HDD. The caveat with HDDs is that they are pretty okay in terms of sequential operations, but do terribly in random operations. And it is random reads that determines your overall system responsiveness. ReadyBoost intends on improving just this, so you want to make your intermediate storage medium have as much random read performance as possible.

Random reads and writes are measured in iops. HDDs usually fall between 300-2000; SSDs can typically do 50K-100K. This is why SSDs are so much more responsive. How many iops you can get out of your SD card is not only dependent on the quality of the card, but also that of the card reader. Sadly, if your card reader is USB based, I would not expect any more than 5K. So I would say the performance improvement you get would be very limited.

Another thing to note is that USB and SD interfaces are really not designed to be permanently connected. You can very easily accidentally unplug them, in which case I really don't think ReadyBoost will like that.

Alternatively, I would simply recommend to go buy a larger capacity RAM module and swap out the one you currently have, assuming RAM is not soldered on your laptop. That would be much more effective and reliable while only needing slightly more effort.

cyqsimon

Posted 2017-10-11T21:45:42.170

Reputation: 203

Sadly, the laptop only has one RAM slot. So I can't just "top up" the RAM - I have to replace it. And that's one heck of expensive. The SD card is nearly an order of magnitude cheaper. Accidentally unplugging the built-in SD card reader does not seem likely. But I take your point regarding limitations as it might well be USB-based inside. – Mikhail Ramendik – 2017-10-12T11:30:19.613

1ockquote>

"You can very easily accidentally unplug them, in which case I really don't think ReadyBoost will like that." I'm happy to let you know that ReadyBoost won't care. There is never anything in the system that is only on the ReadyBoost cache, so if the SDcard (or USB storage key) being used by ReadyBoost disappears, the OS will just fetch what it needs from the hard drive.

– Jamie Hanrahan – 2017-10-13T00:44:27.803

Please be aware that the only thing ReadyBoost does is provide more space for SuperFetch to work in. Without RB, SF is limited to repurposing some of what WIndows considers "available" RAM. SF never has priority access to RAM over ordinary paging, so if your apps have to page in a lot of stuff, SF's performance suffers. RB will speed up your system to the extent that your system's apparent speed is limited by disk I/O operations that can be cached by SuperFetch, but which SF can't find room for. – Jamie Hanrahan – 2017-10-13T00:47:53.747

@RickBrant wow. I wasn't aware MS actually made ReadyBoost fail-safe. Nice to know! – cyqsimon – 2017-10-15T16:07:26.730

@cyqsimon Conversely, this is why Windows won't let you put a pagefile on a drive it thinks is removable. (There are ways to fool it, but you shouldn't!) Pagefile contents might not be available anywhere else, so if the drive gets removed, anything that's been paged out could suffer - this could include the paged pool, which could result in a system crash. – Jamie Hanrahan – 2017-10-15T17:34:20.260

1Also; I must say that "300-2000" IOPs would be highly optimistic for a hard drive. With typical drives, average rotational latency of 5+ msec and seek of 12 msec, the only way to reach much above 100 IOPs is by a series of IO requests that are carefully designed to minimize those latencies - or by satisfying all the requests in the drive's cache. These are just not realistic scenarios. I don't know why you say ReadyBoost is "not recommended". It can help significantly in "marginal RAM" situations, and it can't possibly hurt. I suggest revising your answer. – Jamie Hanrahan – 2017-10-16T20:30:19.970

@RickBrant Your suggestions are quite valid and valuable, but I wouldn't change my final recommendation. When talking about IOPs I was referring to simple test software results, along the lines of CDM and such, in which case due to caching modern HDDs can push 500 IOPs or more. You wouldn't expect a consumer SSD to push 50K IOPs continuous in a realistic setting would you? In addition, W10 already does a fantastic job in disk defragmentation and paging management - last time I did a W10 update for a client, it was obvious that W10 ran much smoother on HDD than W7/8.1 did. – cyqsimon – 2017-10-17T20:10:16.203

Therefore I still don't think the performance improvement Mikhail would get out of ReadyBoost would be worth the effort. Maybe, if the card and the reader have good performance, there would be a somewhat noticeable improvement. But considering the costs of such hardware and all the aforementioned downsides, I still don't think it's worth it. Ultimately the choice is his. If he identifies as a tinkler, then go ahead, but be warned that the benefits may be very limited. Otherwise just leave the laptop as is, or save up for a RAM upgrade. – cyqsimon – 2017-10-17T20:18:45.897

What's the laptop model? Is the RAM non-replaceable? Is there no empty RAM slot? – Christopher Hostage – 2017-10-11T22:04:16.657

Although SD cards do have a limited number of write cycles, the chances of you burning out one "every few months" is nigh on impossible unless you're writing data out to it 24x7. Every few years would be more realistic and, even then, very pessimistic. – Richard – 2017-10-11T22:07:53.927

With 4gb of RAM, you will see no visible improvement. – Keltari – 2017-10-11T22:47:27.487

To ReadyBoost or not to ReadyBoost?

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