Compressed data reduced your IOPS. Is the drive slower at handle compressed data, or is your OS the bottleneck because its compressing all data before sending to hardware? I appreciate that you might not care exactly where the problem is, but it'd be good to know if SSDs suck just for realtime-encrypted file systems, or for any non-compressible data such as MP3s, JPEGs etc.
Also, how does your encrypted-fs affect HDD performance?
Don't get me wrong, an SSD was definitely worth it over an HDD. Despite being slower than the advertised speeds by a lot, it is still far better than before. I'm just saying that paying extra for a "tier 1 performance" SSD may not be worth the money over a mid-range one if that extra performance is gained by the controller doing aggressive compression (as the sandforce-based SSDs apparently do).
The reason that I know that this is not just encryption overhead is because when asked about lower performance being seen by users who were not encrypting, OCZ staff confirmed on their forums that benchmarks not using compressible data will see lower numbers.
I googled a bit and saw that it's widely documented that sandforce are compressing right in the controller, and this allows it to physically do less reading/writing, which artificially inflates the data transfer speed.
Attempting to compress encrypted data has no effect on the size of the data whatsoever, so tests doing that are more reflective of their actual performance.
Comments
Compressed data reduced your IOPS. Is the drive slower at handle compressed data, or is your OS the bottleneck because its compressing all data before sending to hardware? I appreciate that you might not care exactly where the problem is, but it'd be good to know if SSDs suck just for realtime-encrypted file systems, or for any non-compressible data such as MP3s, JPEGs etc.
Also, how does your encrypted-fs affect HDD performance?
Don't get me wrong, an SSD was definitely worth it over an HDD. Despite being slower than the advertised speeds by a lot, it is still far better than before. I'm just saying that paying extra for a "tier 1 performance" SSD may not be worth the money over a mid-range one if that extra performance is gained by the controller doing aggressive compression (as the sandforce-based SSDs apparently do).
The reason that I know that this is not just encryption overhead is because when asked about lower performance being seen by users who were not encrypting, OCZ staff confirmed on their forums that benchmarks not using compressible data will see lower numbers.
I googled a bit and saw that it's widely documented that sandforce are compressing right in the controller, and this allows it to physically do less reading/writing, which artificially inflates the data transfer speed.
Attempting to compress encrypted data has no effect on the size of the data whatsoever, so tests doing that are more reflective of their actual performance.