Ask Me About Windows Vista (and Extender 360)

[Jeremy Charette]

<div class='os_post_top_link'><a href='http://www.thenears.com/archives/175/' target='_blank'>http://www.thenears.com/archives/175/</a><br /><br /></div><i>"While it’s not vista, I’ll talk about that here too since that’s where I got the most information that was new to me and I was assured by the product team that I could blog about everything I saw with respect to MCX on 360. That also means you’re welcome to ask me questions about the 360 to which I might actually be able to respond. Some of these features and details I hadn’t seen confirmed anywhere but maybe I just haven’t been reading enough. Here’s my lowdown on the XBox 360 Media Center Extender based on what I saw last week."</i><br /><br /> <img src="http://www.digitalmediathoughts.com/images/x2.jpg" /> <br /><br />As usual, it looks like Microsoft has been busy crossing the t's and dotting the i's. The Xbox 360 MCX interface is shaping up to be the best yet, with more powerful hardware backing it up than has ever been seen in a Media Center Extender. As far as I know it's the only MCX that can stream HD video. One thing I really have to agree with Peter on however: if you plan on streaming HD video through your home network, <i>don't</i> do it wirelessly. I recently attempted to do this using a wireless multimedia device and my mixed 802.11b/g home network, and it was a disaster. Stick with wireless G at the very least, or bust out those ethernet cables if you can stand the clutter. You'll thank me later.

[[email protected]]

I've heard somewhere that a DVD generates a 9 Mbit datastream and I've also heard 1080p is six times the resolution of DVD so that would max out 802.11g at 54 Mbit.

[Felix Torres]

I've heard somewhere that a DVD generates a 9 Mbit datastream and I've also heard 1080p is six times the resolution of DVD so that would max out 802.11g at 54 Mbit.

Point of fact: 802.11g does *not* deliver 54Mbps.
That is merely the theoretical maximum bandwidth of the channel.
Out of that you need to allocate bandwidth for security, routing, and packet transmission protocols, to say nothing of retries.

Real world, a nice clean WiFi-g setup will deliver an honest 22-26 Mbps, sustained, with momentary peaks into the 30's or 40's. Combined with the Media Center protocols, this is just barely enough for HD video. Most of the time. But glitches will occur frequently.

802.11a is a bit better and can deliver around 40Mbps over short distances, which is why MS recommends it as the preferred solution for video streaming, although it too is strained, with limited margin.
This is why the XBOX360 wireless networking adapter is of the a/b/g persuasion, btw; MS expects anybody serious about wireless video will most likely start with "G" and upgrade to "A".

Some folks might get lucky though and get a stable setup with "G".
Either way: caveat emptor.
Safest choice is 100base-T wireless.
Also the cheapest: A good 50-foot cable can be found for under $10 and 250 feet for under $20.

[Felix Torres]

Red alert!

Application delivery – I had originally thought that the MCX bits would ship in firmware, but it turns out that for the first time in my life I was wrong. In fact, when you select the Media Center Extender option in the XBox it ships you the code for the extender from the media center pc to the XBox at that time. If you have a hard drive, it will cache the code to the hard drive. If you have just the core system, it will download those bits every time. It will not download bits to a removable memory module (I asked, out of curiosity since I probably won’t be buying a hard drive if/when I get a 360). For those of us with no hard disk, the code download should add “a few seconds” to the connection experience to media center every time.

Yes, it is a good thing that the MCX code can and will be dynamically updated over the life of the 360...
...but...
It is less than good that the non-HDD version of the 360 will take a "few seconds" every time you go to MCX-mode. (5 seconds? 120? more?) Also that even the version with the HDD needs broadband to get going in the first place. (Maybe the code will come pre-cached on the drive with the demos and freebies they're promising?)

This will also impact folks without broadband that are looking to set up home media networks. Admittedly few, but I just happen to know several people in that situation; they get video by satellite and the local phone company is outrageous on their DSL rates...

Hopefully, at some point, they will provide the ability for the MCE PC to do the client-app caching locally instead of having to go out over LIVE! every single time you fire up a non-HD 360. And cook up a version of the app that *can* reside on a memory card or attached USB mass-storage (say a cheap thumbdrive.)

Nice to know this up-front...

[[email protected]]

I've heard somewhere that a DVD generates a 9 Mbit datastream and I've also heard 1080p is six times the resolution of DVD so that would max out 802.11g at 54 Mbit.

Point of fact: 802.11g does *not* deliver 54Mbps.
That is merely the theoretical maximum bandwidth of the channel.
Out of that you need to allocate bandwidth for security, routing, and packet transmission protocols, to say nothing of retries.

Real world, a nice clean WiFi-g setup will deliver an honest 22-26 Mbps, sustained, with momentary peaks into the 30's or 40's. Combined with the Media Center protocols, this is just barely enough for HD video. Most of the time. But glitches will occur frequently.

802.11a is a bit better and can deliver around 40Mbps over short distances, which is why MS recommends it as the preferred solution for video streaming, although it too is strained, with limited margin.
This is why the XBOX360 wireless networking adapter is of the a/b/g persuasion, btw; MS expects anybody serious about wireless video will most likely start with "G" and upgrade to "A".

Some folks might get lucky though and get a stable setup with "G".
Either way: caveat emptor.
Safest choice is 100base-T wireless.
Also the cheapest: A good 50-foot cable can be found for under $10 and 250 feet for under $20.

I didn't mean to say g would be good enough, quite the opposite. For me and my tin-foil hat it's wired all the way. ;)

[Felix Torres]

I didn't mean to say g would be good enough, quite the opposite. For me and my tin-foil hat it's wired all the way. ;)

Oh, I got that.
I was just pointing out that it is worse than it appears to be.
Some folks might want to do non-HD video over G and then wonder why it doesn't quite work... :wink:

[Jeremy Charette]

I've heard somewhere that a DVD generates a 9 Mbit datastream and I've also heard 1080p is six times the resolution of DVD so that would max out 802.11g at 54 Mbit.

That depends, but in this case, that's wrong. What you're talking about is actually called "bit rate", and most DVDs generate a 3-5 Mbps bit rate during playback. SuperBit DVDs are encoded at a higher bit rate, which gives them better detail with fewer compression artifacts, but doesn't leave as much room on the DVD disc for extras (like behind the scenes footage, alternate language soundtracks, etc.). These SuperBit DVDs play back at 5-9 Mbps.

Now, what I don't know is at what bit rate Windows XP MCE encodes HDTV broadcasts. Even more importantly, I don't know what bit rate is supported for HDTV broadcasts in Windows Vista. Nonetheless, my point is this:

HDTV programs in MCE won't be recorded at 54 Mbps, so don't worry so much about maxing out your network bandwidth. WMV HD video is encoded at 6-11 Mbps, even the 1080p files. If you're streaming HD video to your Xbox 360, you'll be able to stream WMV HD files just fine over a wireless G or A network. From recent experience, I can tell you that a B network will just not cut it.

Assuming that you are not streaming multiple HD streams around your wireless home network, a G setup should be just fine. If you plan to have multiple Xbox 360s streaming multiple recorded HD shows at the same time, better upgrade to A or ethernet. (No other MCX can play back HDTV files.)

[klinux]

I didn't mean to say g would be good enough, quite the opposite. For me and my tin-foil hat it's wired all the way. ;)

Ditto. I plan to shuttle a lot of contents around in my network and during the remodel, I made sure there are at least one gigabit ethernet jack in each room!

[[email protected]]

I didn't mean to say g would be good enough, quite the opposite. For me and my tin-foil hat it's wired all the way. ;)

Ditto. I plan to shuttle a lot of contents around in my network and during the remodel, I made sure there are at least one gigabit ethernet jack in each room!

klinux, I've heard that gigabit LAN require cat 6 STP, but network-dude at work says it doesn't matter over short distances. Shielded is a bi**h to set up especially since the whole chain needs to be shielded, outlets, switches, dropcables and so on. How did you set up your LAN? Have you tested the bandwidth?

[pnear]

Red alert!
Also that even the version with the HDD needs broadband to get going in the first place. (Maybe the code will come pre-cached on the drive with the demos and freebies they're promising?)

I think you've misunderstood my thoughts there. The code will be downloaded over the local network only from the MCE to the 360. Broadband internet is not involved necessarily (except of course for windows updates that may periodically need to be downloaded). It will work out of the box without any broadband connection. Without a local network connection to the MCE machine, an extender won't work, so I don't see this as a big deal.

But yes, I'll be interested to test a hard drive version against an non-hard drive version to see what the boot up time difference is.

Pete

[Felix Torres]

I think you've misunderstood my thoughts there.
Pete

:wink:
Not the first time that happens.
Okay, downloading the client from the MCE is fine.
(My office mate will be relieved to hear this.)
The idea of populating a house with core 360s as extenders is once more a viable option. ;-)
Still would be nice if a thumb-drive or USB drive could substitute for the HD caddy. The way flash pricing is trending things could get interesting circa 07...

Thanks for setting me straight.