USB2 fast enough for 1080p?

Christo

Christo

Christo

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Returning some videotapes
I am thinking about buying a Western Digital external Hard drive (the cheaper version that uses USB2). I am going to use this to store all of my media, this will include some HD content - previews etc. My question is, will USB2 speed be quick enough to support direct playback at 1080p?

Cheers guys:)
 
Sounds like a maths problem..

1080p has ~ 2 million pixels. Monitor refresh rate is 60 Hertz. Therefore 2 million x 60 "bits" are required per second (120,000,000).. or 120 megabits/sec (120Mbps). This is more than USB 2.0 (480Mbps).

So, in an ideal world.. yes. But my understanding is that USB 2.0 does not actually achieve 480 Mbps - have a google for real transfer rates and how this is affected by processor power (as USB has a significant processor overhead, unlike firewire).
 
james.miller said:
well, if a 360 hd-dvd drive can stream 1080p over usb2.0 im confident in saying yes, its more than capable:)
Click to expand...

Valid point but can you tell the different between 720 over 1080? I think with that statment we need some hard facts how much data is transfered in that USB connection cable.
 
can i see the difference? i cant see how that has anything to do with it lol. the drive doesnt do any processing, it just streams the data off the disc. the films are all 1080p, at least the ones i have are. datarate according to powerdvd is up to 30mb/sec
 
pcAnywhere said:
Sounds like a maths problem..

1080p has ~ 2 million pixels. Monitor refresh rate is 60 Hertz. Therefore 2 million x 60 "bits" are required per second (120,000,000).. or 120 megabits/sec (120Mbps). This is more than USB 2.0 (480Mbps).

So, in an ideal world.. yes. But my understanding is that USB 2.0 does not actually achieve 480 Mbps - have a google for real transfer rates and how this is affected by processor power (as USB has a significant processor overhead, unlike firewire).
Click to expand...

Nooooo!!!

This is a pathological case. Nobody uses uncompressed video in the real world (well, not for storage). You're more likely to be using 30Mbps at the very most (A hypothetical MPEG-2 encoded Blu-Ray rip would be a bit under 30).

USB2 can handle it fine.
 
pcAnywhere said:
Sounds like a maths problem..

1080p has ~ 2 million pixels. Monitor refresh rate is 60 Hertz. Therefore 2 million x 60 "bits" are required per second (120,000,000).. or 120 megabits/sec (120Mbps). This is more than USB 2.0 (480Mbps).
Click to expand...

There is more than 1 bit per pixel for uncompressed video.

For 1080p movies, 1920x1080 pixels x 24 frames per second x 24 bits per pixel

= 1,194,393,600b/s or rather 1.2Gb/s.

However the video is compressed until the cpu+gpu decompresses it, so the data rate is only around 20Mb/s max.
 
Last edited:
Energize said:
There is more than 1 bit per pixel for uncompressed video.

For 1080p movies, 1920x1080 pixels x 24 frames per second x 24 bits per pixel

= 1,194,393,600b/s or rather 1.2Gb/s.

However the video is compressed until the cpu+gpu decompresses it, so the data rate is only around 20Mb/s max.
Click to expand...


its upwards of 30mb/sec. i've seen vc1 hd-dvd titles peak above 30
 
Id've hoped it would be 36Mb/s for blu-ray video at its supposed to be the minimum iirc, but I've heard reports of hd-dvd movies being less than 20GB.
 
well, whats the highest average throughput of a SATA2 HDD? like 80MBS?

look at a slower 5400RPM drive with smaller buffer, USB connects, etc and although it may be OKAY for the most part i would tend to copy the Movie to a local SATA hdd and then play from there to avoid any issues tbh
 
I wouldn't worry about it no matter what drive we are talking about.

Remember 30Mb/s is 3.75MB/s. Even my first pc hdd in 1998 could handle that.
 
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