is 8mb cache worth it?

[Guest]

Tom's HW review of West. Dig. new 8mb cache drive is pretty positive- is the cost really worth it? what say you all? anyone have one?

 

[Lars_Coleman]

I would have to say that if you are looking for low end SCSI performance ... it would be a good way to go.

Just remember, today it's the 8MB cache. What is it going to be tomorrow? Someone else will come out with something that KILLS that drive.

<font color=red>People and hard drives are like bandwagon fans and sports!</font color=red>

 

[AMD_Man]

Yes, there will always be something better that will come in the future, but for now Western Digital makes the fastest IDE hard drives. In my opinion, they are worth it because the hard drive is one of the more major bottlenecks in a PC. You can never have a hard drive that's fast enough. Of course, it might be cheaper to get two 40GB (or 60GB) hard drives and set them up in a RAID 0 for twice the performance and capacity.

AMD technology + Intel technology = Intel/AMD Pentathlon IV; the <b>ULTIMATE</b> PC processor

 

[Ncogneto]

Raid does nothing for access speed therefore you really don't get 2x the performance. You will get a higher STR but not many apps are STR limited. Ide raid is the new "hot" item of the day. Other than running benchmarks, how much of an improvement do you really see?

It's not what they tell you, its what they don't tell you!<P ID="edit"><FONT SIZE=-1><EM>Edited by Ncogneto on 03/10/02 02:05 PM.</EM></FONT></P>

 

[Guest]

but I don't think they make that small a drive with 8mb of cache...- looks like 8mb only comes with 100gb HD's

 

[AMD_Man]

but I don't think they make that small a drive with 8mb of cache...- looks like 8mb only comes with 100gb HD's

I know, I was talking about getting two small 2MB cache drives and setting up a RAID. It won't improve access time, as Ncogneto mentioned, but it will significantly improve sustained trasfer performance, which is a bottleneck.

AMD technology + Intel technology = Intel/AMD Pentathlon IV; the <b>ULTIMATE</b> PC processor

 

[Guest]

hmmm, interesting proposition- b/c I'm getting the asus a7v333 new motherboard with RAID... that two 40gb HD's idea would definitely be a LOT cheaper...

 

[kief]

I see a vast improvment in overall system performance with both SCSI and IDE raid. I have SCSI in my main machine and they is so fast it isnt even funny. If DOES improve seek time SLIGHTLY if you are using RAID 0/1 cuz it can grab from whichever disk is closest to the data. RAID 0 does not improve seek, but when the transfer rate is important for many apps, and even the ones it isnt if the disks can read the data more quickly it can move on the the next task qucikly also. There is a great benefit if you are paging memory as well! The IDE RAID is not as impressive as SCSI but still I think well worth it.

Jesus saves, but Mario scores!!!

 

[Ncogneto]

If DOES improve seek time SLIGHTLY if you are using RAID 0/1 cuz it can grab from whichever disk is closest to the data

This is impossible and a commonly misunderstood aspect of RAID be it SCSI or IDE RAID.

RAID 0 does not improve seek, but when the transfer rate is important for many apps, and even the ones it isnt if the disks can read the data more quickly it can move on the the next task qucikly also

huh? you just said above that it did improve access, again not possible. And tell me when is a high sustained transfer rate neccesary? As for moveing to the next one more quickly as you put it, this is were seek times make a difference.

It's not what they tell you, its what they don't tell you!

 

[AMD_Man]

And tell me when is a high sustained transfer rate neccesary?

Moving large files, accessing the page file, opening a game, saving a game, opening large documents, opening large database apps, compiling a large program, saving large documents (multi-megabyte presentations for example), etc.

As you can see, RAID does provide better performance in many tasks.

AMD technology + Intel technology = Intel/AMD Pentathlon IV; the <b>ULTIMATE</b> PC processor

 

[AMD_Man]

And tell me when is a high sustained transfer rate neccesary?

Moving large files, accessing the page file, opening a game, saving a game, opening large documents, opening large database apps, compiling a large program, saving large documents (multi-megabyte presentations for example), etc.

As you can see, RAID does provide better performance in many tasks.

AMD technology + Intel technology = Intel/AMD Pentathlon IV; the <b>ULTIMATE</b> PC processor

 

[kief]

You will notice I am talking about 2 different raid levels! Let me expand and clarify a bit on the ideas I set forth in my first post.

First when running RAID 1 (mirror) any good RAID controller is going to grab the data from whichever disk (head) is closest to the data, thus improving seek tiem slightly. This effect is fairly random and cannot be measured due to the amount of chance involved. This also applies when running RAID 0/1, but NOT 1 cuz neither drive has all the data (or either pair in the case of 0/1) like in 1. This is the fastest common RAID level. I like 5 as well but thats another story as most IDE controllers dont support it.

We are all familiar with RAID 0 as that is what gives the biggest part of the performance increase and the most common debated here. It give you a much higher transfer rate but does nothing for seek time. Now what I was talking about here is the if you are an average user that is surfing and checkingmail at the same time the disk is gonna be asked to cache stuff and modify your large mail file. While RAID 0 does not help in finding those files faster, it does transfer them faster when the file is larger then your stripe size. This in effect allows the disk to get doen with the read/write faster once it finds the data, allowing it to move on to the next file read/write operation.

While the effect isnt that big in some things just cuz we as users are slower at doing some things then the computer. However when multitasking, paging, using large files, starting the horribly bulky Microsoft OS of your choice amoung the others AMD_Man mentioned.



Jesus saves, but Mario scores!!!

 

[Ncogneto]

Ok, then you mean raid 01 you throw me by the 0/1. I thought it to mean either raid 0 or raid 1. But still, after enough access's, the access time will still average out the same.

It's not what they tell you, its what they don't tell you!<P ID="edit"><FONT SIZE=-1><EM>Edited by Ncogneto on 03/10/02 08:34 PM.</EM></FONT></P>

 

[Ncogneto]

1)Moving large files

perhaps, that is if you have another device capable of writing at the same speed as your stripe is reading, this would requite two stripes. Otherwise it is wasted.

2)accessing the page file
I kind of glad you stated it that way, see above about access times and raid levels. Here access times are nerely as important as STR, and proper optimization of the cache file is necessary, a stripe will do you nothing if your page files is fragmented.

3)opening a game
A bit, is one to three seconds it takes to open the game really going to make that much differnce?

3)opening large documents, opening large database apps,

What apps? what data bases? We are talking about the typical user here ( at least I was)

4)compiling a large program

See above

Look I never said RAID did not have its merits, only that MOST people did not need it, and for them does not justify the cost. Morever the apps you suggest that benefit from it most people would not be caught dead using Raid level 0 as it offers absolutly no fault tolerance and no redundancy of Data,ergo, you are twice as likely to loose all your data in the case of disk failure.

It's not what they tell you, its what they don't tell you!

 

[AMD_Man]

1)Moving large files

perhaps, that is if you have another device capable of writing at the same speed as your stripe is reading, this would requite two stripes. Otherwise it is wasted.

Well, copying the file onto another folder will speed up.

2)accessing the page file
I kind of glad you stated it that way, see above about access times and raid levels. Here access times are nerely as important as STR, and proper optimization of the cache file is necessary, a stripe will do you nothing if your page files is fragmented.

True, true.

3)opening large documents, opening large database apps,

What apps? what data bases? We are talking about the typical user here ( at least I was)

Microsoft Access? Oracle? AutoCAD? Hmm, I guess I'm not a typical user.

3)opening a game
A bit, is one to three seconds it takes to open the game really going to make that much differnce?

It should significantly improve a slow loading game such as UT.

you are twice as likely to loose all your data in the case of disk failure.

Hmm, it depends on how you look at it. Sure, if you have 2 drives instead of 1 then there's twice the chance of one failing, but look at it this way:

If you have one large hard drive and it fails then you've just lost all your data. If you have two smaller HDs in RAID 0 and one fails, you also lose your data. The end result is the same, so I don't see an advantage or disadvantage here.

AMD technology + Intel technology = Intel/AMD Pentathlon IV; the <b>ULTIMATE</b> PC processor

 

[Ncogneto]

Oracle? AutoCAD? I'm sorry, I didn't realize so many people used autocad

If you have one large hard drive and it fails then you've just lost all your data. If you have two smaller HDs in RAID 0 and one fails, you also lose your data. The end result is the same, so I don't see an advantage or disadvantage here.

The disadvantage is that B is twice as likely to happen as A.

It's not what they tell you, its what they don't tell you!

 

[AMD_Man]

Oracle? AutoCAD? I'm sorry, I didn't realize so many people used autocad

Actually, I'm not the one who uses them, my dad does.

AMD technology + Intel technology = Intel/AMD Pentathlon IV; the <b>ULTIMATE</b> PC processor

 

[kief]

How about decompressing a file? Encoding video? Installing a patch (the patch extracts first)? If your disk is optimized and you have a 600 meg page file? Everyone hates to reboot, cut a third off win2k load... Downloading music and video? Once morpheus or kazaa or whatever is done it writes the file again, reading from the temp file and writing the final file...hear those heads grind. I dont like what I am doing interupted! How about data backups? How about copying a file over the network, which a normal disk could do fine, but still be able to play a game or anything else while it goes in the background without any lag? How about letting other people at you home share video or music without it lagging you? Or burning a disk, listening to music, encoding a movie and playing a game at the same time while your buddy watches a movie off your disk, someone is downloading files off PTP programs and the virus scanner kicks in? You laugh at that last one maybe but I have done all that and more at the same time on my machine! Each program asking a little of the disk subsystem at the same time adds up. Any user who often hears thier hard disk grinding away and already has enough ram is a good fit for RAID....

Now another aspect is the user who doesnt want to come home to a crashed hard disk and all data lost. Sure there are backups, but a mirrored set RULEZ. Hard disk dies? It switches to the other, get the drive RMAed and when you put it back in you can sync em again. NO down time!! IDE RAID runs you an extra $20 for onboard which isnt bad. Drives are also CHEAP!

Jesus saves, but Mario scores!!!

 

[Ncogneto]

almost everything you listed there Raid would have a minimal impact on if it were the only logical drive on the system. If it existed as a second logical drive then yes it would help but then so would just another second logical drive non RAID. Another case in point MOST Ide raid controllers are based in software, kind of a WinRaid so to speak. They themselves extract a toll on your CPU much more so then a single disk. Sorry, I am just not buying into the whole cheap 20 dollar ide raid speal. In alot of cases your OS ( win2k,xp) can actually do a better job of handling it( a software raid stripe) by itself!

It's not what they tell you, its what they don't tell you!

 

[kief]

Keep in mind a hardware RAID chip wont use much CPU compared to software, also win 95/98 dont have software raid and win2k pro only has striped no data protection, server does have mirrored. I am not sure about XP. Also keep in mind I am stressing MORE then one of the above activities at the same time.

One point I dont get is you say "almost everything you listed there Raid would have a minimal impact on if it were the only logical drive on the system" which false, although I do have multiple drives in my machine. If I am decompressing a file it reads the original data about much faster and then writes the output data about much faster! How is that not making a difference? The fact that the drive is reading one file and writing another to the same drive at the same time is what makes the speed of a striped set so important!!

The most important thing about RAID is I work on systems with and without, and I myself notice a difference on a daily bases. As one small example if I download an 800 meg SVCD I can decompress it in well under a minute!!

Also remember that the question asked (the topic of this thread) was about was the 8meg cache worth it? Well 2x60 gig 7200 drives plus the raid chip are a similar cost to the one 120 gig wd drive. The seek times on the smaller drives are slightly better plus the data transfer rate will exceed the one 120 gig. So in relation to the topic similar seek times and a faster transfer rate for the same price = better bang for your buck!

In any case I think I have made my case fairly well and with this latest post have made all the points I can think of. I certainly respect differing viewpoints as variety in thought is good and everyones right, I am glad to have a little differing opinion so other may learn from our debate =) Hopefully we can get some others to post thier opinions on the subject to broaden this discussion. Anyone out there reading this have any real life experience with raid or some other opinions?



Jesus saves, but Mario scores!!!

 

[Ncogneto]

Keep in mind a hardware RAID chip wont use much CPU compared to software

Agreed but what are you refering to as hardware? an Onboard Raid controller chip? If so this is not harware raid.

win2k pro only has striped no data protection

Incorrect you can software mirror a drive in either 2k or xp

One point I dont get is you say "almost everything you listed there Raid would have a minimal impact on if it were the only logical drive on the system" which false, although I do have multiple drives in my machine.

you listed so many I would have to dissect them one by one. suffice it to say many of the apps you listed would be much better served by two logical drives existing on seperate controllers and not two drives striped as one. The access times of going back and forth on one striped set would negate the fast read times( in the case of when you were dealing with dual read requests being place on the striped set)

To clarify a point, I never stated Raid was a waste, it has use for a limited amount of users. Add to the mix IDE raid and there software based controllers and this list becomes even smaller. Take a good look at the crazy saw toothed bench results being posted by so manyusers of IDE raid. This is do to the fact the controller is doing a terrible job and handling the striped set. I have done quite a bit of playing around with it myself, right now I am sitting by an 8 drive FC-AL array with a 4 drive stripe, a two drive stripe and two logical drives.

It's not what they tell you, its what they don't tell you!

 

[kief]

From disk manager's help file:

<begin cut and paste>
You can mirror volumes only on computers running Windows 2000 Server.
<end cut and paste>

Notice it says only server, not pro.....If you could do it in pro I would only have my SCSI raid card in here, but instead I have both SCSI and IDE cuz I wanted to add cheap storage =)

Jesus saves, but Mario scores!!!