Anvil's Storage Utilities

[flamenko]

If "many" would say that, then "many" would be wrong. You are arguing with Ao1 who looked in depth at that very question.

Data compressible by Sandforce controllers is relatively rare for most users day-to-day SSD writes. About the only commonly compressible data is OS and program installs (not day-to-day things for most users, just very occasional), and database and VM applications, which if those are in use, they are usually power users and are well aware of the compressibility of their data. Most users do not run large databases or VMs.

John W. my old friend... So what you are saying is that, according to Ao1, the typical user utilizes incompressible data more often in typical things such as ...ohhhh I don't know.... system starting, system software such as explorer and e-mail use and even MS Word file creation?

[Ao1]

John W. my old friend... So what you are saying is that, according to Ao1, the typical user utilizes incompressible data more often in typical things such as ...ohhhh I don't know.... system starting, system software such as explorer and e-mail use and even MS Word file creation?

Whilst I believe compressiblity for client applications is limited my statement was based on 0 fill. I am always prepared to be enlightened if you can tell me how an end user benefits from 0 fill. Name one application in which it is relevant and in which the IOPS are utilised and I will change my view.

[Ao1]

First, a sincere apology to Anvil for derailing his thread and detracting from ASU, which is a great benchmark for end users, providing flexibility and ease of use.

The SNIA tests are beyond an end users ability to undertake, but I believe this is the benchmark that vendors should use for their specifications. The benchmark is something that all major SSD vendors have contributed towards and it provides granularity and comparative performance assessments that are beyond any other method of testing.

Here is a shot of 17 drives that were tested with the SNIA specification using 65% reads/ 35% writes. (17 SSD’s and one Enterprise HDD [edit: in yellow]) It is clear to see that there is a significant difference in performance between SSD’s.


http://www.brighttalk.com/webcast/23848%20

Here is a shot of a Sandforce drive. Blue is incompressible. Red is a data base pattern and the green line is 0 fill. Interestingly 0 fill is close to the data base load, but the max IOPS come out at ~35K. Sandforce specify 60,000 burst/20,000 sustained (@4K blocks) for the SF2x drives and 30,000 burst/10,000 sustained (@4K blocks) for SF1x drives.



Sandforce don’t state how they arrived at their specification figures, but presumably they were obtained on a FOB drive using 0 fill. The SNIA test is based on steady state, which is the representative condition of a drive in use.

To prevent Anvil’s thread from being further derailed there should be a separate thread to discuss SNIA. There is already a thread to discuss SF compression.

[johnw]

John W. my old friend... So what you are saying is that, according to Ao1, the typical user utilizes incompressible data more often in typical things such as ...ohhhh I don't know.... system starting, system software such as explorer and e-mail use and even MS Word file creation?

System starting is almost entirely reads. MS Word files are already compressed. Email, without attachments, is a VERY small amount of writes, and the attachments are usually incompressible.