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abetterlie
Dubstep.breakcore.explosion.soup



Registered: 01/05/08
Posts: 298
Loc: on the internets
Last seen: 6 years, 9 months
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SSD drives, another chapter of deception in storage technology
#11941134 - 02/01/10 10:14 AM (14 years, 1 month ago) |
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SSD drives, like RAID arrays are a lie. Data reads are incredibly fast, yes, but for day to day use, they blow hard.
Many people argue with using the Linux kernel compilation as a significant benchmark for anything. It doesn't actually test anything specifically, the processor speed, multithreading, it's an IO intensive task... There are millions of reasons not to use it. The only reason I am, is because I have recompiled the kernel about 25 times in the last 24 hours. (thank god for 8 core boxes and the -j8 switch).
I have swapped 10k 150GB raptors in favor of Intel X-25M ssds and my performance has dropped, critically. Copying 50MB file over SCP inexplicably falls to write speeds of 500B/s (those are bytes gentlemen). My biggest gripe is when I compile the kernel and run iostat:
Linux 2.6.18-164.11.1.el5.centos.plus (newnewCG) 02/01/2010
avg-cpu: %user %nice %system %iowait %steal %idle 4.16 0.00 0.46 7.05 0.00 88.33
Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn sda 36.64 267.79 3055.00 611931 6980928 sda1 0.10 0.85 4.77 1940 10896 sda2 0.03 0.73 0.00 1677 0 sda3 36.51 266.03 3050.24 607890 6970032
This is about 10 minutes after cc has exited. What the fuck? 7% iowait?? If I type reboot at this moment, the box will hang for 5-9 minutes while the filesystem catches up with the rest of the system. I've tried this with kingston cheapo ssds as well, and the results are the same. I was wondering why after upgrading my development box at work to an ssd, shit like youtube and flash started to lock firefox for minutes at a time. Now I know. The reason for these lies is that the block size on an ssd to prevent premature wear is set to about 1MB, which means that if a write is smaller than 1mb, than the ssd has to clear a meg, write your file, and then write some other data to fill the 1meg block.
Has anyone else experienced this with their ssd? I'm so pissed about this. It has seriously added to my misery, and for production critical servers, I'm going back to 10k raptors.
-------------------- "I'm gonna clear the air, with the metal that's known to divide the whole atmosphere, and I love to share, them bullets come dime a dozen I kept 2 so I could have spare."
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abetterlie
Dubstep.breakcore.explosion.soup



Registered: 01/05/08
Posts: 298
Loc: on the internets
Last seen: 6 years, 9 months
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Re: SSD drives, another chapter of deception in storage technology [Re: abetterlie]
#11941139 - 02/01/10 10:15 AM (14 years, 1 month ago) |
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PC Perspective's review of Intel's X25-M SSD, a custom-designed solid state drive, showed that the manufacturer's sector remapping actually lowered overall performance dramatically over time as the drive became irreparably fragmented.
Some background info. First, sector remapping—a custom solution from Intel— is a method that makes sure wear and tear on the drive is spread over the entire space instead of just in a small area (which would cause the drive to fail earlier). Intel's algorithm unfortunately makes files become fragmented eventually, and defragmenting software currently on the market just screw things up further.
Intel says it's working on a solution, but currently customers with the X25-M can only completely wipe the drive and start fresh in order to reclaim that lost performance. It's not a death knell to SSDs, since the problem can (theoretically) be fixed by either allowing defragmentation software access to the distribution algorithm so as to actually defragment, or having the SSD controller keep track of the fragmentation in the first place and try and minimize it.
http://www.pcper.com/article.php?aid=616
-------------------- "I'm gonna clear the air, with the metal that's known to divide the whole atmosphere, and I love to share, them bullets come dime a dozen I kept 2 so I could have spare."
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arainbow
Hippy


Registered: 02/04/08
Posts: 691
Loc: Palnet Earth
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Re: SSD drives, another chapter of deception in storage technology [Re: abetterlie]
#11941336 - 02/01/10 10:57 AM (14 years, 1 month ago) |
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well I guess you should start reading the on line hard ware reviews (before you spend money and time ) it's all over the web that solid state hard drives are still in the alpha state of development they will be supper speed demons when they finally get them working BUT for now they are no more than a good idea
-------------------- There is more joy in heaven over one of us perfected, than over ninety-nine naturally evolved angels.
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abetterlie
Dubstep.breakcore.explosion.soup



Registered: 01/05/08
Posts: 298
Loc: on the internets
Last seen: 6 years, 9 months
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Re: SSD drives, another chapter of deception in storage technology [Re: arainbow]
#11941385 - 02/01/10 11:04 AM (14 years, 1 month ago) |
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Simply untrue. Early reviews were primarily gushing with how the storage problem was solved forever. I did my homework, and these were the best disks available.
-------------------- "I'm gonna clear the air, with the metal that's known to divide the whole atmosphere, and I love to share, them bullets come dime a dozen I kept 2 so I could have spare."
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frith
God

Registered: 10/27/09
Posts: 7,512
Loc: Philadelphia, PA
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Re: SSD drives, another chapter of deception in storage technology [Re: arainbow]
#11941996 - 02/01/10 01:11 PM (14 years, 1 month ago) |
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Quote:
arainbow said: well I guess you should start reading the on line hard ware reviews (before you spend money and time ) it's all over the web that solid state hard drives are still in the alpha state of development they will be supper speed demons when they finally get them working BUT for now they are no more than a good idea
yeah i dont know what reviews youve been reading..
im not really a fan of ssd because it is still too new and expensive. i can get performance that is very very close (or even better) and has 1000xs the storage capacity for a hell of a lot less money.
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arainbow
Hippy


Registered: 02/04/08
Posts: 691
Loc: Palnet Earth
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Re: SSD drives, another chapter of deception in storage technology [Re: frith]
#11942807 - 02/01/10 03:43 PM (14 years, 1 month ago) |
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the reviews on the linux web sites I don't give any credibility to the sites that run adds for the OEMs just way too much conflict of interests for them to be honest
-------------------- There is more joy in heaven over one of us perfected, than over ninety-nine naturally evolved angels.
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