Maximum PC

Does anybody how fast my harddrives write speed has to be to capture uncompressed hd video from my xbox with this capture card?

I'd say pretty much any drive that spins at 5400RPM or higher will work fine, but 7200RPM or higher would be recommended (I know you were asking about write speed, not spindle acceleration speed, but this should help anyway). The main factors to consider, in all actuality, are the combination of CPU, HDD and RAM. You'll want to have decent or better speed in those as a combination. HD a/v is intense, so yeah, I think you may want to have a decent or better system.

ok well i know some people have said you need a least four hdds in raid 0 for it to work...but i dont know.

That's just plain absurd, I mean, beyond absurd really, it's lunacy! The video is by far NOT that fast and intensive, otherwise the 360 itself would have a hard time processing it and then churning it out. Yeah, that's some real crazy talk there. Don't get me wrong, a 4xhdd RAID 0 configuration can potentially be a rocking powerhorse, but I very highly doubt it's anywhere near necessary for that thing to give you that kind of quality and capability. It's possible that they also had crappy CPU's and RAM as well, and had to over-compensate with the HDD RAID 0 config.

I agree with PM_DMNKLR but let me say this its not really the RPM of the HDD that make the most effect, although it's usaully tied into the total throughput. Random and sequential write speeds are what you need to look at. But again like PM_DMNKLR said I would say you need atleast a dual core CPU, 3GB of RAM or more and a decent HDD. The biggest thing after the aforementioned parts IMO is the video capture card. Do you homework!

I'd even go so far as to say that an add-in card such as that, if it did in fact require such an extreme setup as a 4xhdd in RAID 0, would not sell very well either. While there are a lot of us who do have that kind of kickass capability, the vast majority of people who'd buy that device most likely do not.

from their website:



PCIe 1.0 1x lane is 250 MB sec. PCIe 2.0 1x lane is 500 MB sec. it uses that interface (PCIe 1x) but does spec which version.

HD 1080p at 24 fps needs 1.5 Gb/s, which is 375 MB/s. more or less.

so you may very well need a smokin drive array. 2 generation 3 (latest) SSDs in RAID 0 would do it. for spindle drives 4 in RAID 0 seems right. remember, you said uncompressed.

check me math though, its late, and Im off to bed.

I have an Intensity Pro in my Mac Pro. I coupled it with 3x 1tb 7200:12s. With 2 750gb drives in Raid 0, uncompressed HD video from a camcorder would occasionally drop frames.

Are you doing a live stream? There's no reason that it should be doing that, or that you'd need to use that card for that purpose. I know a guy who uses straight firewire from his HD camera, which he records in 1080p, on his MacPro, which is only 3 or 4 years old. He never has any quality loss issues at all, and the only gripe he's ever had is that he wishes it would be lightning fast, instead of taking roughly 1/2 hour to transfer 2 to 3 hours' worth of data. That's a lot of data though, so it's typical.

I think they're talking about actually recording it as it happens so to speak. Not just copying transferring files.

If it's for live streaming that he's seeing frame drops, that's understandable, unless it's enough to cause hiccups. You're not always going to see something HD in 1080p running at it's peak framerate, constantly, through the entire stream. Just cuz one doesn't see the drop doesn't mean it didn't happen. Are the drops noticeable? And I know that OSX is awesome for a lot of things, but even the MacPro's have only so much they can handle at one time. What else is this guy doing on his machine that could cause a hiccup, if it's anything major?

Correct

Ok, so if you're needing to capture uncompressed HD video from your Xbox (360 I presume?), then why would you need a drive speed, for recording, that's at least 5 to 10x the speed of the unit that's creating and processing the video output?

I'll be honest with you though, having a 360 myself and having used it a lot on 1080p tv's, large screens and small, it's not as impressive as it should be. I've played a lot of games in 1080p, that I didn't like on that resolution, because it caused more images' details to show more naturally, which, unfortunately, it showed too much detail and basically made certain parts look like crap.

I hope you can get your answer though, or at least are able to make a good, sound decision.

apparently you do not understand how blu ray discs store video data and how the players actually play back the content. or how the xbox, or any video card or video playback system for that matter, generates HD resolution video from games or disc. the data used to generate the video stream and the data actually in the video stream itself can be, and usually is, vastly different.



what are you talking about? video over HDMI (what we are talking about) has a constant framerate. there is no "peak" framerate. it does not vary for a given resolution.

read this pdf for starters (the adobe hidef white paper from 2004). it explains why a fast RAID system may be needed for real time uncompressed HD video storage. 100-160 MB/s sustained write speeds are needed to capture uncompressed 1080 HD in real time depending on the format/fps. again, that is sustained write speed, not burst.

There are no "true" 1080P games for the Xbox 360 so far, correct me if Im wrong.
Games are rendered in 1280x600p and then upscaled.
And I was taking uncompressed 1080p video straight into the Intensity from a camcorder.

what was the resolution/color depth, frame rate and connection type? HDMI?

there are a few that are rendered in 1080p, but not many.