Software HardDrive Compression

[Dobyvatel]

I recently compressed my entire C drive in Windows XP, I didn't really need the space, I just wanted to see what it would do to performance, since then I have noticed lower access times to data, although this is completely oppinionated, I was wondering if anyone ever benchmarked it on newer 2.0 GHz plus systems, does it really hinder, or does it help.

My thinking is since the HD is the bottleneck for computer systems today, if the drive is compressed it takes less time to get the data from the drive to the CPU, and with plenty of extra clock cycles to kill, the CPU can uncompress the data and use it before and uncompressed drive could transfer it. compression works from 10-20% compression, saving 10-20% of the time for data access might be benefitial, although I have trouble believing it would actually boost perfomance.

And thoughts, ideas, or maybe an article that benchmarks before and after?

 

[ElFenix]

you could bench it for us but you'd have to find some sort of bench that access the drive a lot... a timedemo won't do it as those usually load everything into ram beforehand anyway...

 

[MonkeyK]

Sheesh, the things people risk for performance; first Raid 0, now this.

Compressing your drive is generally not a very good idea. If for some reason, you are unable to start your system, and have to boot from a removable disk, you will be unable to get to your data. You probably also would not be able to get to your data if you moved the HD to another machine.

-Mike

 

[Dobyvatel]

Your right that it might be riskier, but then again, just having a HD thats not backed up is risky as well. You can do RAID 1 but that still volnerable to corruption, so thats not really that great either, although less likely to cause problems. The only way to really have secure data is to back up regularly, and keep a history, wich I do, taken that I have an independent file server with RAID 10 and regular backups (daily), I'm not to worried about my system going down, and if it did, I wouldn't waist time moving my HD to another system, I would reformat and reinstall, nice and clean. Although your right, a lot of people depend on their data, and afterwards are completely lost when they loose it all. For now, I'm just conserned with having the most bang for the buck on my workstation, but thanks for your consern

Partly it's for the sake of discussion as well, if it doesn't hurt to test the limits, then why not!?

 

[zephyrprime]

Years ago, there was a product called Stacker that offered much better compression than the scheme used in XP. For some reason, the compression used in XP and NT is really poor. Anyway, plenty of benchmarks were done back then to see how these drives compared to uncompressed drives. This was before the internet became widespread so there are no online reviews from this era. Anyway, the results were mixed. Things were usually a little slower but if the drive was particularly slow to begin with, it could be sped up by compression. Also, Stacker made a hardware decompression addon board that gave enough of a speed boost so that using compression would actually make a drive faster than not using compression. But I think benchmarks like those are troublesome because I wonder if the benchmark tests wree just writing test data that was all zeroes. If that were the case, the data would be extra compressible and make for unrealistic results.

This was all back in the days of the 386 & 386sx so it's hard to say what kind of performace we would see in modern systems.

 

[SearchMaster]

I had this discussion with a Microsoft engineer recently. He said that compressed drives do indeed have better performance, in certain circumstances, due to the reasons you outlined. It depends on a variety of factors, file sizes being a key one.

 

[Ben50]

A lot of web servers do a similar compression when they send out html to clients. Since the bandwidth is more of a bottleneck than the processor, it makes things go faster. As with all compression, it only works well on files that are highly compressable such as text files or graphics files. If they are already compressed like gifs or jpegs it will only lessen performance though.

 

[AndyHui]

Originally posted by: MonkeyK
Sheesh, the things people risk for performance; first Raid 0, now this.

Compressing your drive is generally not a very good idea. If for some reason, you are unable to start your system, and have to boot from a removable disk, you will be unable to get to your data. You probably also would not be able to get to your data if you moved the HD to another machine.

-Mike

Compression in NTFS is not risky. It's built into the file system and does not affect data access in any way.

 

[glugglug]

NTFS compression is done file-by-file, not on the drive as a whole, so it is much safer.

The biggest downside is the recompression process after each time a file is modified tends to get the drive fragmented quickly, so you have to defrag much more often on an NTFS drive flagged to have everything compressed.