I seriously doubt Xbox 360's ability to do 1080p

  • Thread starter Thread starter AirRaid Mach 2.5
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* Zomoniac:
I presume you're an American then, and have different rules. In the UK
you can't get HDTV without HDCP.
Click to expand...

This has _nothing_ to do with the country. Seems you didn't understand
what "HD Ready" means. Of course nowhere in the world the "HD Ready"
logo is _required_ for HDTV, not in the US, and not in the UK. "HD
Ready" simply means that the device accepts a digital video signal with
HDCP encryption over HDMI or DVI. A HDTV TV set without "HD Ready" logo
is still HDTV, though, but without HDCP support and HDMI/DVI it's not
allowed to carry the logo. This is the case everywhere in the world.

So all the HDTV TV sets with analog component inputs are still HDTV,
even without "HD Ready" logo. They just lack the logo and can't display
encrypted HDCP content. But that doesn't mean they are not HDTV.

Besides that, the value of "HD Ready" for customers is exactly zero as
HDCP is just a copy protection system. HDCP also works with blacklists
so it's possible that some day your nice "HD Ready" device won't display
encrypted content any more because the movie industry thinks that this
device isn't secure enough any more...

Benjamin
 
* Chris F:
no, he's right, if a tv does not boast a HDMI port and a resolution
capable of displaing at least 720p, it can't be "officially" badged as
being HDTV ready in the UK, which is basically a way of showing that
the set is "futureproof"
Click to expand...

"HD Ready" != HDTV ready...

Benjamin
 
What a load of bollocks. HDTV does not mean HDCP. Try telling your theory to
the hundreds of thousands of HDTV owners around that are currently watching
HDTV on their telly that does not support HDCP...
Click to expand...

"HD Ready" does mean it has to have HDCP.
 
* Zomoniac:


This has _nothing_ to do with the country. Seems you didn't understand
what "HD Ready" means. Of course nowhere in the world the "HD Ready"
logo is _required_ for HDTV, not in the US, and not in the UK. "HD
Ready" simply means that the device accepts a digital video signal with
HDCP encryption over HDMI or DVI. A HDTV TV set without "HD Ready" logo
is still HDTV, though, but without HDCP support and HDMI/DVI it's not
allowed to carry the logo. This is the case everywhere in the world.

So all the HDTV TV sets with analog component inputs are still HDTV,
even without "HD Ready" logo. They just lack the logo and can't display
encrypted HDCP content. But that doesn't mean they are not HDTV.

Besides that, the value of "HD Ready" for customers is exactly zero as
HDCP is just a copy protection system. HDCP also works with blacklists
so it's possible that some day your nice "HD Ready" device won't
display encrypted content any more because the movie industry thinks
that this device isn't secure enough any more...

Benjamin
Click to expand...

What on earth is everyone going on about?! You said yourself, in the
above post, that for a TV to be labelled "HD Ready", not just "HDTV",
it has to carry HDMI with HDCP.

I pointed out that MS said "Xbox 360 supports HD Component video
output, which is
compatible with nearly every HD ready TV on the market today. That's
not yet true for HDMI."

and commented on their strange choice of wording. They didn't say every
HDTV, they said every HD *ready* TV, did not have HDMI. Which, as you
said yourself, it has to, by very definition. Yes, I know I'm just
being a pedantic twat, but nobody actually seems to understand what I'm
talking about and going on about something completely different.
 
Zomoniac said:
Yup, but for a TV to be HD Ready it has to be able to display HDTV, which
means HDCP.
Click to expand...

I'm not sure Freeview HD will be HDCP'd. I don't think that it has been
during the trial anyway.

Shak
 
Shak said:
I'm not sure Freeview HD will be HDCP'd. I don't think that it has
been during the trial anyway.
Click to expand...

Yeah but for Freeview HD (Terrestrial HD for anyone outside the UK who
doesn't know) that's gonna have to wait until all analogue stations switch
off starting in areas around the UK in 2007 and finishing in 2012. That's
if they're still on track with that, mind you...
 
Skipai Otter said:
Yeah but for Freeview HD (Terrestrial HD for anyone outside the UK who
doesn't know) that's gonna have to wait until all analogue stations switch
off starting in areas around the UK in 2007 and finishing in 2012. That's
if they're still on track with that, mind you...
Click to expand...

Yeh, alright. I was just disagreeing with all HDTV having to have HDCP. In
fact, can't you watch Sky HD over component too?

Shak
 
Yeh, alright. I was just disagreeing with all HDTV having to have HDCP.
In fact, can't you watch Sky HD over component too?
Click to expand...

Probably. But sooner or later the big film studios will start telling
Sky that they want their content encrypting, and so to watch it you'll
need HDMI or HDCP over DVI. HD Ready (NOT the same as HDTV) is a mark
given to futureproofed TVs, a label that is awarded only if a tv a)
supports 720p minimum AND b) supports HD content through an analogue
connection AND c) supports HDCP protected content over a digital
source. Only if ALL three criteria are met can it be badged "HD Ready",
it's a standard to show that a set is futureproof and will still be
usable in a few years when HDCP over HDMI becomes compulsary (probably).
 
Wouldn't the fact that this bandwidth has to be shared between CPU and GPU
have some sort of effect? PC video cards have dedicated video memory -- they
don't share it. The 360 has to share this bandwidth and I'll bet the GPU has
to access this shared memory *frequently*.
 
Wouldn't the fact that this bandwidth has to be shared between CPU and
GPU have some sort of effect? PC video cards have dedicated video
memory -- they don't share it. The 360 has to share this bandwidth and
I'll bet the GPU has to access this shared memory *frequently*.
Click to expand...

It's been designed with high speed CPU/GPU access in mind. I've not got
the exact numbers to hand but I know that the original XBox had 6.4
GB/s memory bandwidth which was shared between the CPU and GPU. Since
the 360 is considerably more advanced that the original XBox I would
presume 3 GB/sec bandwidth between the CPU and the graphics mem is not
a problem. Consider that you can buy things like upscaling DVD players
which can output 1080p - they are basically performing the same task..
ie decompressing the data and copying it all up to a RAM buffer at 50Hz
or whatever. The XBox is considerably more powerfull than your average
upscaling DVD player.
 
Bus contention would still be a problem, the GPU and CPU cannot be accessing
system memory simultaneously. For one thing, the more pixels we're pushing
the more AA has to be performed. I'll bet this is one of the reasons the 360
can't do more than 2xAA, and can't do Adaptive AA or temporal AA at all.
Does the 360 do any anisotropic filtering at all?
 
Bus contention would still be a problem, the GPU and CPU cannot be
accessing system memory simultaneously.
Click to expand...

It depends on how many DMA channels there are. The original XBox had 4
so I wouldn't expect the 360 to have any trouble with this.
For one thing, the more pixels we're pushing the more AA has to be
performed. I'll bet this is one of the reasons the 360 can't do more
than 2xAA, and can't do Adaptive AA or temporal AA at all. Does the 360
do any anisotropic filtering at all?
Click to expand...

Yes. Even the original XBox had anisotropic filtering.
 
All DMA implies is that the CPU doesn't have to get involved in
device-to-memory transfers, obviously this is a good thing, but it doesn't
do much for the fact that the GPU is processing MASSIVE amounts of data from
system memory. Hell, even AGP memory was relegated to mere texture storage,
but in the 360 everything the GPU processes is in system memory. Anisotropic
filtering, AA, textures, per pixel lighting/shading all of these involve the
GPU reading/writing to system memory. Some of these operations can't even be
done in one-pass which only adds to system memory thrashing.

It's too bad no one can verify MS's marketing "specifications" about the
360. I'd love to see some SPECint or SPECfp benchmarks for the 360 or even
some memory benchmarks for that matter.
 
All DMA implies is that the CPU doesn't have to get involved in
device-to-memory transfers, obviously this is a good thing, but it
doesn't do much for the fact that the GPU is processing MASSIVE amounts
of data from system memory. Hell, even AGP memory was relegated to mere
texture storage, but in the 360 everything the GPU processes is in
system memory. Anisotropic filtering, AA, textures, per pixel
lighting/shading all of these involve the GPU reading/writing to system
memory. Some of these operations can't even be done in one-pass which
only adds to system memory thrashing.

It's too bad no one can verify MS's marketing "specifications" about
the 360. I'd love to see some SPECint or SPECfp benchmarks for the 360
or even some memory benchmarks for that matter.
Click to expand...

After about 0.01 nanoseconds on Google I found this:

http://features.teamxbox.com/xbox/1145/The-Xbox-360-Dissected/p6/

GPU-Graphics RAM bandwidth = 256GB/s
Main memory bandwidth = 22.4 GB/s

Kinda makes that 3GB/s 1080p spec seem trivial eh ?
 
Duh, the 256GB/s is to 10MB of EDRAM. It's basically a glorified
framebuffer. How many textures can you store in 10MB? I don't think you can
even process ANY form of AA at 1080p in 10MB (hint AA involves sampling MORE
pixels than are acutally present, some forms of AA require 6 times the
amount of data per pixel, per color, to be useful it should be 4 times the
number of pixels present [which for 1080p won't fit in 10MB of anything).
Guess you've got a lot to learn don't you?
 
Duh, the 256GB/s is to 10MB of EDRAM. It's basically a glorified
framebuffer. How many textures can you store in 10MB? I don't think you can
even process ANY form of AA at 1080p in 10MB (hint AA involves sampling MORE
pixels than are acutally present, some forms of AA require 6 times the
amount of data per pixel, per color, to be useful it should be 4 times the
number of pixels present [which for 1080p won't fit in 10MB of anything).
Guess you've got a lot to learn don't you?
Click to expand...

yeah martin, get a clue about programming!
 
pigdos said:
Duh, the 256GB/s is to 10MB of EDRAM. It's basically a glorified
framebuffer. How many textures can you store in 10MB? I don't think you can
even process ANY form of AA at 1080p in 10MB (hint AA involves sampling MORE
pixels than are acutally present, some forms of AA require 6 times the
amount of data per pixel, per color, to be useful it should be 4 times the
number of pixels present [which for 1080p won't fit in 10MB of anything).
Guess you've got a lot to learn don't you?
Click to expand...

Oh dear. You've just gone and messed yourself right up, 'PigDo'.
 
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