Quantcast

Maximum PC

It is currently Sat Oct 25, 2014 6:32 am

All times are UTC - 8 hours




Post new topic Reply to topic  [ 6 posts ] 

SSDs: Which is more important in determining how fast an SSD is?
Sequential read/write speeds 0%  0%  [ 0 ]
Number of IOPS 50%  50%  [ 1 ]
Neither really tells you how fast an SSD is 50%  50%  [ 1 ]
Total votes : 2
Author Message
 Post subject: Which spec is best in determing which SSD is fastest?
PostPosted: Mon Sep 24, 2012 4:51 pm 
Coppermine
Coppermine
User avatar

Joined: Wed Mar 25, 2009 4:40 pm
Posts: 714
So I'm wanting to get another SSD, but I've noticed a couple things.

First, the latest generation of OCZ SSDs (Vertex 4 & Agility 4) have lower sequential read/write speeds than the previous generation (Vertex 3 & Agility 3).

Second, MaxPC recently posted two articles (Samsung 840 SSDs & RunCore's Kylin III) where they primarily refer to the IOPs.

For everyday use, to which one should I pay attention?

Feel free to take the poll, leave a post, or both! Thanks!


Top
  Profile  
 
 Post subject: Re: Which spec is best in determing which SSD is fastest?
PostPosted: Mon Sep 24, 2012 4:57 pm 
Smithfield
Smithfield

Joined: Sun Jun 18, 2006 7:37 pm
Posts: 5396
It depends on the operation you're primarily concerned about. Are you doing large transfers? Then obviously speed is most important. Are you doing a lot of random activity such as file serving? Then IOPS are more important.


Top
  Profile  
 
 Post subject: Re: Which spec is best in determing which SSD is fastest?
PostPosted: Wed Sep 26, 2012 5:17 am 
Clawhammer
Clawhammer
User avatar

Joined: Fri Sep 23, 2005 6:22 pm
Posts: 4406
Location: In the closet
What ^he^ said. In my experience, most users on a daily basis benefit far and away by IOPS. How often do you really transfer large gigabyte sized files anyway, right?


Top
  Profile  
 
 Post subject: Re: Which spec is best in determing which SSD is fastest?
PostPosted: Wed Sep 26, 2012 7:59 am 
Team Member Top 500
Team Member Top 500
User avatar

Joined: Thu Jul 21, 2005 10:45 pm
Posts: 3036
Location: Central Florida
kleinkinstein wrote:
What ^he^ said. In my experience, most users on a daily basis benefit far and away by IOPS. How often do you really transfer large gigabyte sized files anyway, right?


Conversely, how often do you transfer thousands of 4K files???

RE thread title / OP: First thing to realize is that all SSD manufacturers rate their read/write speeds based on Atto benchmark best transfer rate. However Atto has no bearing upon real-world performance. This is why Vertex 3 can show numbers like 500/550MB/sec while the Vertex 4 only shows 475/535MB/sec. Yet in real-world performance, the Vertex 4 (since firmware version 1.4 - currently at 1.5 which has been included on new drives for several months) is up to 30% faster, Crystal Disk Mark & AS-SSD are both much better at corelating an artificial benchmark data into real-world performance numbers.

Second thing to realize is that IOPS doesn't mean much for the average user either. Most mechanical hard drives can't even touch 1,000 IOPS, yet for 99% of home users, mechanical drives provide more IOPS than they can ever use. IOPS is usefull mainly for large servers where multiple requests for data may occur simultaneously.

The only useful metric in determining SSD performance is online reviews from trusted sources.

Beyond that, you have to look more deeply into the details of each SSD, stuff like, what controller does it use, what brand of NAND is used, what type of NAND is used (Toggle, Asynchronous, Synchronous, etc...), SLC, MLC, or TLC, speed of the NAND, etc... etc... etc...


Top
  Profile  
 
 Post subject: Re: Which spec is best in determing which SSD is fastest?
PostPosted: Wed Sep 26, 2012 8:42 am 
Smithfield
Smithfield

Joined: Sun Jun 18, 2006 7:37 pm
Posts: 5396
chaosdsm wrote:
The only useful metric in determining SSD performance is online reviews from trusted sources.

Unfortunately, the only review website that I came across that actually does something as close to a comprehensive real-world stress test is Anandtech. Everyone else seems to use benchmark tools.

Like let's take this snippet of the Samsung 840 Pro 256GB review. Under heavy workload conditions, it averages at 154MB/s reads, 389MB/s writes. Huh. That's a far cry from the marketed 540MB/s reads (then again, it probably wasn't sequential either... which your data is never really going to be).


Top
  Profile  
 
 Post subject: Re: Which spec is best in determing which SSD is fastest?
PostPosted: Sat Sep 29, 2012 4:27 pm 
Coppermine
Coppermine
User avatar

Joined: Wed Mar 25, 2009 4:40 pm
Posts: 714
Quote:
This is why Vertex 3 can show numbers like 500/550MB/sec while the Vertex 4 only shows 475/535MB/sec. Yet in real-world performance, the Vertex 4 (since firmware version 1.4 - currently at 1.5 which has been included on new drives for several months) is up to 30% faster

Thank you, all, for the input.

I thought OCZ's switch from Sandforce to Indilinx caused a slight decrease in speeds for the 4 series model, but it would improve in the following series - I guess that could be inaccurate. This is really interesting!

Are there other benchmarks that mimic real-world conditions better?


Top
  Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 6 posts ] 

All times are UTC - 8 hours


Who is online

Users browsing this forum: No registered users and 7 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group

© 2014 Future US, Inc. All rights reserved.