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usb2 anytime ever for netmd?

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Guest Anonymous

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Guest Anonymous

ok, it's late and i'm just not getting something. if it's not even using full bandwidth in usb 1.1 then where is the bottleneck for writing? it would seem to me (but who am i to guess why sony does some of the stuff they do) that they would be able to make a 2x/4x/6x.... netmd recorder.

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I'm not gonna disagree with majestic and bertrik. Net Md probably does not take full advantage of usb 1.1 let alone 2.0. Well i guess that's a mix of advertising hype and false advertising on sony's site. with most technological devices they give you what they believe theortically to be the product's top performance

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I have already posted this, and majestic has commented on it too.

USB1.1 is "theorically" 11Mbps, whereas USB2.0 is "theorically" 480Mbps.

Now, to the math: 11Mbps is able to transfer 1408 Kb per second @ it's full glory and 480Mbps transfers up to 61440 Kb per second.

This all realies in whatever compression mode u use, LP2 or LP4 that is. LP4 uses an ATRAC encoding similar to an MP3 encoded at 66 Kbps. So it is the same bit rate.

Currently, NetMD units do only up to 64x transfer (the high-end ones). So, doing the math, 64x66 Kbps = 4224 Kbps. If u understood up to this point, then ur good. It's certainly easy to see, that a USB1.1 11Mbps bus CAN easily HANDLE a mere 4.2 Mbps :wink:

Now on to LP2:

LP2 uses and ATRAC encoding similar to an MP3 encoded at 132 Kbps.

Using the 64x transfer rate, u'd be up to:

64x132 Kbps = 8448Kbps. Again, a USB1.1 bus WOULD still HANDLE easily 8.5 Mbps (for 11 Mbps).

Now u may ask: Where the hell goes my bandwidth? I have USB1.1, a good USB shielded copper cable, and... Have u thought about ur CPU? U're processor itself? Have u tried encoding an MP3 from a CD to the HDD? Is it done instantainly? NO, IT'S NOT! It requires the processor to encode data into blocks and then join them together in a single file. The faster ur processor is, the fast u'll encode an MP3, the faster u'll encode an ATRAC file to the MD. Currently, a P4 2Ghz, or AMD's counterpart Athlon XP 2000+, encode an MP3 at 128Kbps at 35-40 times! So, u'll still need a faster CPU to handle 64x for LP2 encoded ATRAC files!!! OF course, no USB1.1 and 2.0 will reach it's maximum bandwidth, due to bus that leaves the USB port and goes to the Southbridge or I/O Chipset (ServerWorks motherboards with 64-bit 66/33 Mhz PCI-X slots) on ur motherboard... Clear? :wink:

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Guest Anonymous

ok, i understood everything you said about usb and current pc's. however the question i asked didn't even get touched. let's just say that we have all the horsepower in the world, heck i'll use one of my setup's.

P4 3.2Ghz cpu HT with an 800 MHZ fsb

2 GIG crucia pc 3500 ram running at 400 mhz dual channel

usb2

sata 400 gig hd space

so now that the compression is going hella fast and as it's copying over to the md it converts too. it has the file converted and ready to transfer, now why in gods name can they NOT speed it up?

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Guest Anonymous

I've read the USB 1.1 actually tops out at 48 MBps, but it all depends on the source I suppose. Anyhow... The bottlenecks that I can determine would have to be:

1) The encryption.

-Although most of it's done at the pc, some of it's done in the MD player I've heard.

2) Encoding and decoding.

-Both the minidisc player and the computer do this I surmise from the results obtained via http://www.minidisct.com/forum/showthread....&threadid=16069, because ATRAC2 cannot be PCM raw. Data like that would be far too large to store on an MD.

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i am hoping that the next generation of md, will be some kind of update to make it like netmd2 (what netmd1 should have been which is a list of things which we hope would become reality) along hopefully ubs2, and better interaction with a pc, and more freedom with the files.

that would be quite a nice update... tongue.gif tho i don't think it may come in the near future since the RIAA still have a firm grip around the copyright issues so the "freedom" to transfer music files across freely may not come too soon....

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Either way, USB isn't the bottleneck. The main bottleneck is how there are so many friggin TOC edits...past that, the bottleneck is how fast your computer can encode and how fast the MD unit can actually write. Keep in mind that MD systems were originally designed for 1x recording, period. Writing faster than 500 kbps or so was previously reserved for decks and boomboxes with high speed dubbing, and suddenly we want this tiny unit to write 64x...or roughly 4200 kbps. I bet that's the bottleneck, making such a tiny unit write so fast. Writing to the disc requires heating it up, which requires power, and we're trying to run minidisc units off of 1.5 V sources (one AA battery.)

However, I think Sony is the biggest bottleneck. If they want to speed up NetMD, they can do it. They can kick out the repetitive, unnecessary TOC edits, they can make the software more efficient, it wouldn't be hard for them to do. Sony has really been getting on my shizlist for making their products suck. Speaking of which...out of curiosity, why the hell doesn't someone like Sharp step up to the plate and push the limits of MD systems? Competition drives innovation, and I think Sony is slacking.

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I agree somebody should step up 2 to the plate and pushu the limits of MD. Sharp may be a good candidate, but it's possible to speculate that Sony Electronics have pushed the limits of MD beyond what they have allowed us to see so far, but the main culprit who is preventing MD innovation, is Sony itself... well Sony Music divison that is.

It has been said before the UMD is most likely not going to be backwards compatible with MD, but UMD can use MD characteristics (ATRAC encodineg of sound etc..) . Sony electronics probably can implement UMD traits to the MD.

Major innovations will continue to be stifled as long as Sony Music/RIAA are behind the times. The industry itself needs to catch up with consumer demands. Then we will most likely to see what our beloved little format can really do.

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