[ggfox]

Originally posted by vlxjim
Just to let you folks know you can get real time transfers in best quality. I just setup two TiVo 2 80Hr with two of the Linksys USB200M USB 2.0 10/100 Network Adapters, each hooked to a Linksys WGA54G Wireless-G Game Adapter ....

Hmm....

If the drivers on the TiVos are only USB 1.1, wouldn't that limit the transfer in/out of the TiVo unit's USB ports to the theoretical 12Mbps regardless of the 54Mbps link between the 2 WGA54G units using the bridge setup?

Wouldn't 2.0 drivers be needed for this to work at the desired 54mbps speed all the way through?

Just wondering how this all works..
TIA,
George

 

[ggfox]

Hi,

I understand theoretical -vs- actual speeds. That's was not the point of my post... What I am trying to get at is the fact that the bottleneck in the setup suggested by "vlxjim" (54mbps bridge) is the USB port/driver on the TiVo unit. Thus regardless of how fast your data flies over wireless, the TiVo I/O throughput on its USB ports is limited to what the port/drivers support: USB 1.1 (12mbps). I think his solution does not do much but improve performance just notch over regular 802.11b (11mbps). I don't think the TiVos communicate at speeds beyond what USB 1.1 supports: 12mbps.

This is the way I am looking at it. You just have to follow the chain of devices and their "speeds" under this type of setup:

1. TiVo phys. USB 2.0 port + TiVo USB 1.1 driver = USB 1.1 virutal port = 12mbps max speed (theoretical)

2. Linksys USB200M 10/100 USB-Ethernet + virtual USB 1.1 port (above) = Linksys "fast speed mode" (not "high speed 54mbps mode" per documentation) = 12 mbps transfer rate (theoretical).

3. Linksys WGA54G 54mbps bridge + Linksys USB200M in "fast speed mode" = 12 mbps transfer rate (lower denominator of both devices).

4. Linksys WGA54G 54mbps bridge + Linksys WGA54G 54mbps bridge = 54mbps wireless transfer rate (theoretical)

If I am correct on this, you can see that from point #1, the bottleneck is the USB 1.1 driver built-in to the TiVo. Regardless if your unit has an USB 2.0 port, as long as the driver is 1.1, you can only get 12mbps (theo).

Thus, no matter how fast your data flies over the wireless link (point #4, the two Game bridges), it will only go through (in and out) the TiVo USB port at no more than the supported theoretical speed (12mbps) because of the USB 1.1 driver, and the fact that the Linksys USB200M adapter will only switch to 12mpbs (not 100mbps) when connected to a USB 1.1 port/driver (point #2). The lowest common denominator in this chain is the USB 1.1 driver, so the data will never pass through it faster than its capacity.

However, I do think this setup does improve transfer a little over standard 802.11b adapters. Since the actual (not theoretical) speeds of the 802.11b setup will be definately much less than 11mbps, and the 54mpbs bridge setup should pipe data faster to the USB port, which may then process it closer or perhaps even faster than 11mbps but always less than the max 12mbps supported by the TiVo port (theo). ... but I don't know that this type of performance improvement is worth the extra $$.

Perhaps someone with a hacked TiVo unit can actually run some benchmarks on these scenarios. .. ?

I think until we get USB 2.0 drivers on the Tivo Series 2, this setup will not work at full capacity all the way through the chain of devices. On a side note, it should work on TiVo Series 1 with the TurboNET 100mbps ethernet card in place of the Linksys USB200M USB adapter. Since then you will not have the USB 1.1 port bottleneck, and your slowest device would be the 54mbps bridge (802.11g!)

Regards,
George

 

[ggfox]

Originally posted by pcar1947
In your humble opinion is it worth it to implement "vlxjim solution"? Or do you see a better long tem soluton? Keep in mind I like his solution.

Hi pcar1947,

Well, assuming what I've read is correct in that while TiVo Series 2 have physical USB 2.0 ports, but only USB 1.1 drivers for them. Then the quick answer is no.

If the driver's on the TiVo's are still v1.1, then the USB 2 port will only work at that spec, which supports up to 12mbps of throughput (theoretical). Being that the case, then the ports are the bottleneck in the chain of devices suggested by the solution proposed by vlxjim. So no matter how fast the 802.11g or Ethernet devices communicate (54mbps / 100mbps theo.), they can get or send data to the TiVos at the speed the TiVo ports support (12mbps theo.)

While I do think vlxjim's solution will improve performance a little, I don't think its worth the extra $$$ bucks it will cost to get all four devices in question (two USB2 10/100 adapters, and the 802.11g game bridges).

The speed difference between the supported (and cheaper) wireless solution of 802.11b at 11mbps -vs- the virtual USB 1.1 ports at 12mbps is not that big, even after accounting for the actual -vs- theoretical speeds. Although I believe other factors could make this speed difference better (greater) under certain circumstances, but that's for someone with the setups in place to benchmark.

It all boils down to a simple analogy... Its like having a 54-lane highway full of cars all heading to the same exit which is only 12-lane wide. No matter how fast traffic was on the highway, you get a big slowdown at the exit due to congestion.

I think until we get new USB 2.0 software driver updates for our TiVO units we will not be able to do high-speed (> 12mbps) through the USB ports on the units. Anybody got any info on when this might happen? .. or better yet, has this already happened and I am still in the dark ???

Now, if you have a TiVo Series 1 with a TurboNet 100mbps card, then I think the solution proposed by vlxjim would work well. But unfortunately Home Media Option is not available for Series 1, and the only advantage of this solution for Series 1 would be connecting a hacked unit to a PC over high-speed wireless for transfering recordings, doing backups, etc.

Regards,
George

 

[ggfox]

Hmm....

I have 802.11b at home and never had a problem with signal strength. It always gets about 90% which is just as good as my PCs. I also pick up 4 other networks in the building I live. I guess it all depends on the equipment you are using, location/distance, and setup.

But I agree with you.. if your current wireless equipment is not working well, then something should be done about it. But if my 802.11b setup was weak in signal and slower than average, then I would just buy a signal amplifier/booster (e.g, Linksys WSB24) rather than go with a more expensive all-around replacement which is not going to yield its full capacity due to current bottlenecks.

And you do need two "built-in" drivers from TiVo (USB and adapter). Without them what you plug into your USB (e.g., USBM200) will not work, and most importantly the drivers also determine how adapters work on that bus (speedwise; USB 1.1 = 12mbps, USB 2.0 = 480mbps).

Regards,
George

 

[ggfox]

Originally posted by vlxjim
You not getting the point. With your wireless B network at 100% you still can't get real time transfers in best quality or high quality as far as that gos. Wireless B is just to slow and a signal amplifier/booster won't get you there either.

Hi,
Point was taken and understood. But that was not my point...

All I am saying is that by doing your workaround, you cannot get anything more than 12mbps (theoretical) into or out of a TiVo unit, no matter what kind of device chain you plug into it (100mbps, 54mbps, etc.).

Like you said on your original post: "...the TiVo's USB port is now the bottle neck", ...a 12mbps bottleneck.

I am not debating wether you are getting better performance or not over your old 802.11b setup. I believe you are getting better performance, just not what the high-speed hardware in question supports and that is something that should be clear to anybody who contemplates this solution now; There is a bottleneck, and its the current TiVo USB 1.1 driver. Once that is taken care of, then you can use the high-speed network hardware/setup to its max capacity.

That said, and like I have noted on my other posts, I know your setup has merit and will improve performance over a standard 802.11b setup. You're probably gettings a few extra mbps out of that setup over 802.11b, and that makes a lot of differnce between real and non-real time transfers (considering that an average MPEG-2 DVD is encoded for real-time playback at just only 6 to 7 mbps.) But I also believe that the level of improvement is directly related to how bad the replaced 802.11b setup was performing. For me, I have no complaints with my 802.11b setup. But I know its a different story for a lot of folks out there.

That's why IMHO, for me its not worth the extra $$ (just yet). I will just wait for USB 2.0 drivers from TiVo and then go with the following supported 100mbps wired or 54mbps wireless solution. Hopefully this will just be around the corner (but probably not ) ...For those who don't want to wait, have the spare $$, or definately need more than their existing 802.11b setup, then your solution is definately the best wireless alternative, aside from wired (and perhaps faster) solutions. For those just wanting to get into wireless, I say "think about it". Its definately worth considering and the right solution for many; But just be aware of (#1) the current bottleneck and (#2) the remote posibility that in the future TiVo may drop or not (fully) support the devices you purchase for this solution today.

Plus when TiVo gets us USB 2.0 drivers. The ones that build on a B network well be left in the dust.

Agreed. But I am (and have been for a while) on a 802.11b network. Just not ready to buy hardware that could (but most likely not) be dropped or never supported when they release 2.0 drivers and new network adapter drivers. There are no garantees/announcements for upcoming TiVo support, although I have to admit they have a good record... but kinda slow on delivery

This post was for those that wanted a wireless G network But are still waiting on TiVo for drivers.

My posts were meant to dicuss/clarify the existing 12mbps USB bottleneck which will greatly reduce any wireless-G solution's resulting capacity. I think this thread has accomplished that, and hopefully some folks will find it useful.

When I say that you need no drivers from TiVo for this wireless setup I'm talking about the wireless side TiVo has the drivers for the USB200M they just need to update the chipset driver.

Understood also... Just making the point that such 100mbps ethernet adapter, altho supported by TiVo, will only run at no more than 12mbps.

On a side note, and for those who may be interested, I actually contacted TiVo support to check on the USB 1.1 driver & limit issue, and they responded today. Here's part of the email:

> -----Original Message-----
> From: [email protected] [mailto:[email protected]]
> Sent: Monday, December 29, 2003 1:34 PM
> To: [removed]
> Subject: Re: CID# 114327: TiVo Web Response
>
> Hello George,
>
> Thank you for contacting TiVo Customer Support. I understand
> you would like to verify that the USB drivers on the TiVo DVR
> are version 1.1.
>
> The USB drivers are version 1.1 and can run up to 12mbps. The
> device that is USB 2.0 compatible will work with the DVR but
> only at the 12mbps.
>
> ...

Regards

George