Hard Disc for Capturing

[mtremel]

Im getting ready to by a 7200 rpm drive solely for capturing analog video to. (using iuvcr)
my question is, should i get one large drive (60GB), or two smaller drives (40GB) and raid them?

Thanks
System Specs:
AMD 1400
Asus A7V133
768MB Musking 2-2-2 Ram
Maxtor 80GB 5200rpm & 20GB 5200rpm HD

[sommersby]

One big one is fine, but if you are using fat32 make sure you partition it so you can segment your captures.

[mtremel]

Ohh sorry forgot to say, im using Windows XP, so it will be NTFS...

so the raid will not give me any performace increase over the single,(the mobo has a raid controler onboard)?
wasnt sure if i would get any performance difference by haveing a raid setup....

Thanks for the info...

[TheInformer]

RAID level 0 (also called striping) will definitely give you a performance increase over one drive. Both drives will work in parallel to save your data stream.

For example, if you save a 100 MB file to a single drive, 100 MB is transferred to the drive.

If you use RAID-0 however and save a 100 MB file, 50 megs goes to one drive and the other 50 megs goes to the other drive at the *same* time.

Of course I realize this is simplified and makes a few assumptions, but the general idea is there.

I already have one Maxtor 60 GB 7200 RPM drive, and when I get a RAID-0 controller (or new mobo, haven't decided which) and another 60 GB drive, I'll be setting them up in a RAID-0 configuration.

NOTE: When you set up two drive in a RAID-0 config, they have to be identical drives or you will lose the ability to access the excess space on the larger drive.

[mtremel]

Ok, thanks makes sense....
so in theory i would have less frame drops then...

yes if i go raid i will get two 40's maybe two 60's will depend on my buget for the month, lol....

[sommersby]

You will get a speed increase using raid, but a good 7200 rpm drive will capture at whatever resolution your cpu can handle, and raid does present some of it's own problems, just read the reviews and tests in mags, if you are a gamer then you will see a difference, but for video not noticable, I have a raid setup on my sons puter for gaming, and I have used that puter for capturing also. You can always go with one drive to start with then add another drive at a later date to spread the expence.

[sommersby]

An udate to my last post, it just so happened that the new maximum pc mag I got today covers your question with surprising results, Her it is in a nutshell, a single 7200 rpm drive will always give you faster reads than any raid configuration. In writing though you get a 20 percent increase with a two drive raid in string mode but 10 percent slower in mirror mode, in a 4 drive raid you get 30 percent better write in string and the same 10 percent slower in mirror mode.
So the finale verdict is if you do more writing than reading then raid will help, but it would have to ALLOT of writing to justifie the expence, if you concern is security rahter than speed then a raid is a great choice in mirror mode as your data is written twice, once to each drive, keep in mind thought that using this mode two 80 gig drives still only gives you a total of 80 gig!!
If you play alot of games and do as much reading as writing then a single 7200 rpm drive will give you better performance than a raid setup, this was news to me also, if I had known this I would of never bought a raid setup, read it for yourself, these are the mags words not mine, and maximum pc is a great mag for honest opinions!!

[mtremel]

Thanks for all your info,
i see your point, being that this drive will be solely for captured video(the avi being captured is the only file on the drive,and setup at a maximum NTFS partition), which do you think will give less frame drops, or is the any difference there?
I do play alot of games, and such but they wont be on that drive...

Thanks again....

[sommersby]

If you have the cash and want the 20 percent faster write speed then buy 2 and raid them, but remember, to get that increase you would need 2 drives of 60 gig to get 60 gig total, I have a single 7200 rpm drive and my capture is still limited by my cpu, not my drive, and I have an AMD 1600+xp, I can capture at any resolution without any noticable frame loss. So is the 20 percent worth it, not to me, but the choice is yours, not mine.

[tjdmobile]

Strangely, I have found that my 5200 RPM Western Digital 40 Gig captures perfectly at DVD 720x480 res, and benchmarks almost as fast as my 7200 IBM 41 Gig.

I saved a lot of $$ getting the 5200. Then again, I also always use Huffyuv when I cap, so that might pick up the slack for a slightly slower drive.

I wish I had picked up the 100 gig drive though!

TJD

[therick]

Alright! This is pissing me off! I hear all the time about people capturing at 720x480! I can't even get 640x480! I have an IBM Deskstar 7200 Rpm hooked to a ATA-100 controller...with a write speed of 37mb/sec! Is it my lowly Duron 900 that is holding me back? Or the fact that I am capturing with a bt848? I just can't get to the bottom of this! Frustrating!

[mtremel]

Well with my current config, i am not able to capture at 640x480 for more than 15min (without droped frames)...
at 480x480 it does well (1 or 2 at the most)...
Thats where i thought a better (less filled) drive may give me better results (also being 7200)... And i am using the huffy codec, with yuy2 color, my cpu is a t-bird 1400 with 768mb of ram (so i wouldnt think that is killing me performace wise)...
Well from what everyone says i think i will try one 60gb 7200 and if that does it fine, if not add another down the road and raid them...

Thanks for the info and suggestions everyone =)

[patrickm]

i have to agree that getting a 7200 rpm drive for captures is unnecessary. a good 5400 works just fine. 7200 is clearly better for random read/writes, but large sustained transfers don't benefit as much. i have a WD 60G 5400 with a very high platter density, and it can sustain at least 26Mb/s over the promise channel on an a7v133, which is more than 720x480 @29.97 requires.

my guess would be the bt848 is causing the drops. some vcrs and tv stations can also cause drops becuase of jitter and bad sync signals too. some sound cards can also cause a lot of problems.

how many 'dropped frames' are there in 15min? 1 or 2 is not noticeable, and often is the result of an a/v resync, so a frame may not actually be dropped, just the audio and video clocks readjusted.

[TheInformer]

therick & mtremel,

Check to see if DMA is enabled on your hard drive:

Right click My Computer,
Properties,
Device Manager.

If you're still having problems with dropped frames, it may be your sound card. A sound card can slow down an otherwise powerful enough system for capturing.

Just my two cents...

[Mark W.]

Another two cents.

What capture program are you using?
I have:
PIII 933
BT878 capture card
Maxtor 40G 7200

I use AVI_I0
The other day I was capturing some DV from my camcorder at 480x480. (great job, no dropped frames). 40 seconds into my 3rd sequence I buffed out..."reduce data rate" it tells me....end of capture. Tried again, same results. Went into capture settings and enabled "allign to sector" Tried it again with no problem. Don't know if it was coincidence, but it worked.

I have tried capure at 640x480 and have had captures with no frame drops. For what I do, I use 480x480. Is there something I should know about 640x480? Whutchya makin'?

Mark

[TheInformer]

For captures that have a VCD target, I use VirtualDub and capture using HuffYUV at 352x480.

For an SVCD or DVD target, I use DVIO along with my Sony DVMC-DA1 to capture directly to DV format.

I'm debating on picking up Scenalyzer Live. Any thoughts on this?