The SSD Relapse: Understanding and Choosing the Best SSD
by Anand Lal Shimpi on August 30, 2009 12:00 AM EST- Posted in
- Storage
Power Consumption
SSDs are at their highest power consumption when performing large file sequential writes. The majority of the power consumption comes from writing to the NAND flash and when you’re doing sequential writes you have more flash devices engaged at a time. Thus my peak power consumption test involves measuring power used over the 5V rail while the drives perform my 2MB sequential write benchmark in Iometer and at idle of course.
First, the idle numbers:
The Samsung and Indilinx drives use the least power, while the Intel drives use the most out of the SSDs. Intel honestly just needs to stick some power gate transistors in front of the controller and flash to curb power consumption at idle. They are all still lower than a mechanical drive, and much lower than a 3.5" HDD.
It's also worth noting that given the order of magnitude performance advantage these drives hold over traditional hard drives, they spend far more time at idle than their mechanical counterparts.
Under load the SSDs use anywhere from 2.5 - 3.5W, the exception being the Indilinx SLC drive which comes in at under 2W. Power consumption is roughly half if you switch to a random write workload, and the standings also switch places. While Intel's X25-M G2 draws less power than the OCZ Vertex Turbo in the sequential write test, it draws more power in a random write workload:
| Random Write Power Consumption | Min | Average | Max |
| Intel X25-M G2 160GB (MLC) | 1.55 W | 1.60 W | 1.7 W |
| OCZ Vertex Turbo 128GB (Indilinx MLC) | 1.13 W | 1.17 W | 1.21 W |
As I alluded to before, the much higher performance of these drives than a traditional hard drive means that they spend much more time at an idle power state. The Seagate Momentus 5400.6 has roughly the same power characteristics of these two drives, but they outperform the Seagate by a factor of at least 16x. In other words, a good SSD delivers an order of magnitude better performance per watt than even a very efficient hard drive.
Facebook
Twitter
RSS
295 Comments
View All Comments
Bonesdad - Sunday, October 10, 2010 - link
Been over a year since this article was published...still very relevant. Any plans to update it with the latest products/drivers/firmware? There have been some significant updates, and it would be good to at least have updated comparisons.Well done, more more more!
hescominsoon - Thursday, February 17, 2011 - link
Excellent article but you left out sandforce. I'm curious if this was an oversight or a purposeful moission.PHT - Friday, September 28, 2012 - link
This article is fantastic, the best I ever read about SSD.Any follow up with new SATA III drives and new controllers like SandForce, new Indilinx etc.?
I will be glad to see it.
My Best
Zygmunt
lucasgonz - Wednesday, October 16, 2013 - link
Hello everyone.This post is quite old but I hope someone can answer.
I am concerned about the life of my ssd (sandisk extreme 240). I performed partitions ignoring the issue of the level of wear and partitions. I have it for one year ago with a 30gb partition and one with 200GB. I wanted to use large drive for data but I did not have time for that and just use the first 30gb partition . My question is if the ssd may be damaged by using only a little segment. DiskInfo shows 10tb reading 18 tb and writing.
sorry my poor English.
Thanks for any help.
Ojaswin Singh - Monday, January 13, 2014 - link
Hey,This is the most informative article i have ever read.Can You Please clear Out Some Of my Doubts:-1.Does Playing Video Games or Running Programs add to Writing on the SSD
2.Is 1 Write Cycle=Filling 120GB of SSD once
3.I really write on my HDD a lot(Seriusly a Lot) So how much life cycle can i expect from Samsung 840 SSD(Neither Pro nor EVO) I mean for how much time can i expect it to be writable
Please Help me cause i want the speeds of SSD but i want it to last for me too
Thanks,
Ojaswin