What is the Storage equivalent of dual core?

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wussboy
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What is the Storage equivalent of dual core?

Post by wussboy » Fri Mar 16, 2007 6:13 am

So I got a new computer with an AMD X2 processor. It's pretty nice. My first dual-core. However, I have noticed that a lot of times the performance really chugs because of HD access. Now, admittedly, I don't have the world's fastest HD (newer WD notebook drive), but if I'm installing an update plus moving a movie file plus opening programs, it doesn't just slow down 10%.

It crawls.

On its knees.

Is there a way to buy/build a computer so this won't happen? Is RAID the answer? Are physically seperate HDs the answer? Doesn't all HD traffic go through the same bus anyways?

If anyone knows anything or has any suggestions, I'd love to hear them.

niels007
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Post by niels007 » Fri Mar 16, 2007 7:23 am

Compared to CPU / RAM, any form of harddisk(s) will be very very slow, relatively. Notebook drives are of course noticably worse than a Raptor 10.000rpm drive, or two raptors in RAID.. but reall fluent it won't get, even with RAM based harddrives as mostly the interface (bus) is a bit slow..

While a raptor or other new 3.5'' drive would be noticably faster, it will make a bit more noise as well..

Tradeoffs.. :P

angelkiller
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Post by angelkiller » Fri Mar 16, 2007 7:23 am

If your notebook drive is 5400rpm (a common notebook HDD speed) that is the root of your problem. HDD's in general have not gotten much faster over the years. (compared to CPU's and GPU's) So a HDD may bottleneck your system. Raid 0 would be a good solution, but I cannot recommend it due to it's lack of redundancy. (If one drive fails you lose everything.) A less hassle alternative method would be getting a WD Raptor. At 10,000 rpm, it's fast. Really fast. But if you thought 7200rpm drives were loud........

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Post by mr. poopyhead » Fri Mar 16, 2007 8:47 am

RAID 0 should give you a speed boost. and if you're worried about faults, you can always do RAID 0+1 (striped and mirrored) but then you're up to 4 disks which many not exactly be silent.

angelkiller
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Post by angelkiller » Fri Mar 16, 2007 8:52 am

mr. poopyhead wrote:you can always do RAID 0+1 (striped and mirrored) but then you're up to 4 disks which many not exactly be silent.
Been there. 4 HDD's is NOT quiet. Raid 0+1 is the "optimal" solution form a stoarage/speed standpoing. However, it is not cost effective or quiet.

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Re: What is the Storage equivalent of dual core?

Post by JazzJackRabbit » Fri Mar 16, 2007 9:09 am

wussboy wrote:So I got a new computer with an AMD X2 processor. It's pretty nice. My first dual-core. However, I have noticed that a lot of times the performance really chugs because of HD access. Now, admittedly, I don't have the world's fastest HD (newer WD notebook drive), but if I'm installing an update plus moving a movie file plus opening programs, it doesn't just slow down 10%.

It crawls.

On its knees.

Is there a way to buy/build a computer so this won't happen? Is RAID the answer? Are physically seperate HDs the answer? Doesn't all HD traffic go through the same bus anyways?

If anyone knows anything or has any suggestions, I'd love to hear them.
It crawls because you are accessing two files at the same time (a very simplistic explanation) so seek times are killing you.

Just to experiment, try copying two 700MB files sequestially, one after another, note the transfer times. Now try to copy the same two files at the same time (do copy/paste once for each files), you'll notive that your transfer times increased by an order of magnitude.

Same with installing new updates and moving movie file, windows in order to give you appearance of multitasking installs update and copies time at the same time, this slows down performance considerable because your HDD has to install update at one section of your HDD and you move your movie file at another section, and seeking information for two different tasks at two different locations is killing your performance.

There is no way of getting around it, seek times are always going to be a problem with conventional HDDs, it will always be that way. One thing you can do is make raid, which will improve performance, but will not solve the problem, or keep two hard drives, one for system and one for data, or, a much more sensible solution, just don't do multiple HDD intensive tasks at the same time :)

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Re: What is the Storage equivalent of dual core?

Post by matt_garman » Fri Mar 16, 2007 9:13 am

wussboy wrote:...but if I'm installing an update plus moving a movie file plus opening programs, it doesn't just slow down 10%...
More RAM might help, depending on your typical usage patterns. At least with the opening programs part, with sufficient RAM, your most oft-accessed programs should stay cached there, and not require any disk access (after the first load, of course).

As the others have suggested, a faster disk would probably help. If soft-mounted, the WD Raptors are reasonably quiet.

You can do RAID0 (aka "striping") with two disks for improved performance, but at a greater risk to data. But if you have a decent backup scheme in place, that's not too much of an issue.

Multiple drives should also help, as you could keep your programs on one drive and media on another.

But then again, if your typical computer usage pattern involves tasks that are heavily disk I/O bound (e.g. video editing, music recording & mixing, etc), then I'd say you probably owe it to yourself to invest in a fast disk sub-system. :)

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Post by andyb » Fri Mar 16, 2007 9:23 am

Just get a HD501LJ, its quick, cool and quiet, you can even put it in an enclosure, but if your CASE is good (P180/P150) and under a desk you will barely notice its there.

Gaininge performance using seperate HDD's can be annoying and fiddly and is not worth the effort, simply because to get the performance you have to use BOTH HDD's at the same time but doing different things on each drive - Not recomended unless you are doing repetitive heavy disk usage activities such as un-raring.

RAID-0 will gain a performance increase in completing a single task, but it will still get bogged down by multiple simultaneous tasks.

You are probably better off looking at a Shitachi Deathstar, they seem to have very good performance when the drive is very busy, other drives slow to a crawl.

A Raptor is an option, SCSI is out of the question and isnt really geared up for heavy "single-user" performance.

I would just consider a HD501LJ, for single drive-drive (i.e. un-raring a file from C: to C: ) performance its very very fast and very quiet, how it does on multitasking I dont know I have not tested it, but in SPCR tradition it must be reccommended for its quietness.


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Post by floffe » Fri Mar 16, 2007 4:04 pm

andyb wrote:A Raptor is an option, SCSI is out of the question and isnt really geared up for heavy "single-user" performance.
What he describes is not a traditional single-user scenario, at least not in the sense of single user, single task. It's no many-user scenario like a database server either, though.

A possible solution could be using a good filesystem that can handle several simultaneous transactions without much of a slowing down. I just tested copying two movie files, 700MB and 63MB respectively. When doing it simultaneously it took 5s longer (32+5 compared to 26+6 when doing them sequentially). One should remember that some of the difference there is counted twice though. This is between two ext3 partitions on different hdds in linux.

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Post by andyb » Fri Mar 16, 2007 4:26 pm

More specific information about how drives perform under different circumstances, loads, environments can be found in the 2 links below.

Toms Hardware articles often suck, they didnt used to, (they got very bad a few years ago) they now seem to be holding back the diarrhoea and have recently (last 12 months) improved again, I can say with confidence that their bars and charts are useful........ but as I still dont give them 100% trust, I would pick a drive or 2 that you are interested in and look elsewhere for more info, and some different reviews, like SR below, or search the net.

http://tomshardware.co.uk/storage/chart ... 0&chart=31

Storage Review has been on my regular look at list for a few years, unfortunately they dont get enough funding or get sent new drives, but the results they get are very good, and to my mind as accurate and thorough as SPCR is with quiet PC kit.

http://www.storagereview.com/


Andy

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Post by wussboy » Sat Mar 17, 2007 12:49 am

I realize that if the drive spins faster, it will transfer data faster, but I don't really think it's about seek times. It's really about one drive head not being able to be in two places at once. I think this problem is what I'm interested in opinions on.

Hypothetical question: If I had two physically seperate hard drives and accessed one file on each at the same time, would it still crawl like my computer does now?

If it would, why? What can be done to fix that? Different busses in the mobo?

If it wouldn't, how many seperate drives could I use? 4? One per SATA port?

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Post by andyb » Sat Mar 17, 2007 3:26 am

There is more to raw data transfer rates than just the spin speed, in the same way as there is more to CPU performance than its clock speed.

The data density levels per track, the firmware, the caching, the processor, the algorithms the accuator arm - they are all very important for the drive performance and its noise characteristics.

Seek times/noises.

Apart from rotational latency (spin speed), there are several things that make a drive access data faster or slower than its counterparts, the accuator arm speed is what you hear as "seek noise", the accuator arm moves at "blur speed", the faster its acceleration, speed and stopping the faster it will get to the data. This is exactly the same as someone in a car, but just like car driving there are other elements to overall performance. However the faster its acceleration, speed and stopping the louder and sharper the seek noise will be, which is the main reason why quieter seeking drives are slow seeking drives, they take a lazy approach to getting to the data, maybe 1.5 rotations instead of 0.5

If the accuator arm has got to the correct position to read/write the data it is then waiting for the disk to spin the disk round to the right position so it can actually read the data. From the noise perspective there is no point in rushing, if you have the time take it so the seek can be quieter.

If there is a que of data waiting to be read it is better "overall" to read the data in a "shorter time to each piece of data" technique rather than reading them in the order of requests. i.e. read A-B-C-D-E as thats how the data is spread accross the drive, rather than 4-1-5-2-3 as the requests might be, this allows the drive to make much shorter seeks (physically) but this will also slow down the requests. As A=1 and 5=E, 1 gets a good deal, but D has to wait three requests before the data is retrieved from the drive. Most of the last paragraph is down to the firmware and the algorithms.

You will find that a fast seek time and a high data transfer rate dont always mean a fast drive in real world usage, as there are an awful lot of thing going on behind the scenes that the manufacturer never tells anyone. Likewise synthetic benchmarks are worthless simply because the drive manufacturer can make their drive do very well in that, but might be total crap in th real world (I am cynical).

Likewise manufacturers like Seagate and Samsung who have very high "sequential" data transfer rates use this to their advantage in the algorithms and caching, because they have slow seek times. Other drives have fast seek times but slow data transfer rates, so again they use the benefits of their drive in their ultimate design.

I am no drive genius, but thats most of what you need to know from a quiet PC perspective.
Hypothetical question: If I had two physically seperate hard drives and accessed one file on each at the same time, would it still crawl like my computer does now?

If it would, why? What can be done to fix that? Different busses in the mobo?

If it wouldn't, how many seperate drives could I use? 4? One per SATA port?
No. The 2 drives are seperate entities and so longs as your CPU can keep up (fast single core or any dual), you wont have a problem.

The problem is that you would need to spread your data and programs accross one or more drives, I experimented with this an awful lot about 5 years ago, I had my OS and "Swap File" on one HDD, my programmes and games on another, and my data on a third drive.

This meant (in theory) that If I load a program when my PC is busy (high swap file usage) both drives will be doing different things at the same time (I had a dual CPU system so it was OK with that), I could then fire up a CD-ripping promram and rip data to a third drive.

It worked - it was far quicker than using 1 drive, but that was only the case because I had a dual CPU rig, most systems of the time would not have seen the benefit. But again, to put this into perspective, the way that HDD's work is very different now compared to several years ago. In real terms yes you will get a faster performance by using a similar setup now, but it wont be the quantum leap that I experienced.

The reasons are:

RAM is cheap, you will find a far bigger performance jump by using 2GB of RAM and dissabling your "Page file" rather than having your "page file" on another drive, it is also far quieter.
Drives are so much faster now that once your program has loaded (quicky unless its really big) the drive is waiting for you to use it for data and as you have loads of RAM your drive doesnt need to swap data out to have RAM space to fully load the program into RAM.

Unless you are doing something that is very drive intensive you shouldnt really need more than one drive, are you video/music editing, RARing/unRARing files.???

I have a PC at home that has a 2.5" drive, its got reasonable performance for its tasks, but its drive performance is about half the speed of my main PC and its boot/programmes/games/data 400GB T133 drive which I rarely have to wait for it to do anything, unlike my 2.5" machine which is very slow the moment I ask it to do more than one intensive thing. Movies dont stutter or jump at all when I am unRARing in the background though.


Andy

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Post by Devonavar » Sat Mar 17, 2007 10:55 am

wussboy wrote:Hypothetical question: If I had two physically seperate hard drives and accessed one file on each at the same time, would it still crawl like my computer does now?
No. You're suffering from disk thrashing, which, as you've correctly diagnosed, is the result of the seek head jumping back and forth between two areas on the disk rather than trying to read each file in sequence.
wussboy wrote:If it wouldn't, how many seperate drives could I use? 4? One per SATA port?
As many as you have separate sources of data. If you are doing a lot of non-linear editing with audio separate from video, get one each for video and audio, and one for your OS and programs. If you're editing video that has the audio interleved already, you can get away with a single drive for all video content, and one for the OS and programs. You can also try separating the OS and programs, (or even separate programs), but this is usually more trouble than it's worth, especially in windows. As a general rule, program code is small enough that it doesn't cause much disk thrashing.

Just remember that you need to organize your data very well if you have multiple drives. After a certain point, trying to keep track of where everything is just gets too painful for the benefit of having multiple drives.

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Post by Beyonder » Sat Mar 17, 2007 12:01 pm

mr. poopyhead wrote:RAID 0 should give you a speed boost. and if you're worried about faults, you can always do RAID 0+1 (striped and mirrored) but then you're up to 4 disks which many not exactly be silent.
Although this is an oft-quoted claim, I don't think it's actually true. Here's why.

In a nutshell, RAID-0 increases performance in a single area: sequential transfer rates. However, the above post (which is quite detailed) explains how STR has effectively written itself out of the performance equation for desktop computing. It also dispels some other myths about hard drives not improving substantially (total bunk).

Striping is great for multi-user/server environments, but in a single user environment, it doesn't provide a sizeable benefit. Adding in the increased probability of data loss makes it totally unappealing to me.

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Post by wussboy » Mon Mar 19, 2007 1:57 am

So it is correct that every SATA cable plugged into a physically seperate HD will have (functionally) unrestricted access?

If so, this is good news. I'm completely okay with buying a few drives and organizing my data. I like organizing things!

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Post by Devonavar » Mon Mar 19, 2007 10:06 pm

Yes. There are theoretical bandwidth limits, especially on the Southbridge itself, but your issue isn't bandwidth, but thrashing. Functionally, you should see a massive improvement.

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Post by wussboy » Tue Mar 20, 2007 5:44 am

Brilliant, Devonvar. That's what I wanted to hear. I'll make sure I impliment that knowledge in my next build.

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Post by Trip » Thu Mar 22, 2007 2:57 am

Seek times ought to be pretty good for solid state HDDs from what I've heard.

Access time .11ms is relatively incredible

Finding one right now might be difficult, but I guess they'll be available eventually. The 2.5" version looks the best.

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