Shared Knowledge
"Tivo - File Transfer Speed"
Updated: 3 Nov 2010
Summary: Tivo Series 2 was never designed for a user to transfer and watch a file in real time. If watching while transferring is desired (without Tivo having to pause), the file being transferred must not be a Tivo recording quality higher than "High".
Tivo Series 2:
Tivo or at least the Tivo Series 2 I have, was never designed to play a video (file) as the video is being (transferred) from another Tivo or a PC-based Tivo server. What? Yep. Why do I say this? (A) The processor in Tivo is not a speed demon, nor does it have a lot of random access memory (RAM) to work with and thus does not do 2 things at the same time very well (remember it is always buffering the current channel to memory), (B) the standard hard drive in a Tivo is an older 100Megabit per second (Mbps), 5400 revolutions per minute (RPM) IDE type and this interface has to be shared by Tivo potentially recording the current channel and storing a transferring file, (C) The series 2 does not have a built-in Ethernet port and the USB port used for communications on a Series 2 is only a version 1.1 and limited to 12 Mbps and finally, the USB must either be attached to a Tivo supplied 802.11G wireless adapter (54Mbps) or run through a USB-to-Ethernet adapter (100Mbps max), neither of which is very efficient in communicating large quantities of data.
Best achievable transfer rate without Tivo having to pause:
- Over a my completely 1Gbps Ethernet wired local area network, with the receiver of a Tivo transfer being a PC, I get a 4Mbps transfer rate.
- Where the stored file Tivo is Ethernet wired but the PC receiver is on a 54G wireless, I get 4Mbps transfer rate.
- What this tells me is that: (1) Transfer rate is a function of the Tivo's USB-based file transfer hardware and software and not whether it is wired or wireless and (2) Tivo can not transfer a file at a speed greater than 4Mbps without having to pause.
What is a 4Mbps file?
Tivo recorded - medium quality - 1Gigabytes/hour or 8.0Gigabits/hour
Tivo recorded - high quality - 1.2GB/hour or 9.6Gigabits/hour
Tivo recorded - best quality - 2.5GB/hour or 20.0Gigabits/hour
PC-Based - DVD quality - 3GB to 1GB/hour or (24.0Gigabits to 8Gigabits)/hour
Tivo recorded - medium quality - 8Gigabits/hour = 8Gb/(60 minutes * 60 seconds) = 8,000,000,000/3600 = 2.0Mbps
Tivo recorded - high quality - 1.2GB/hour or 9.6Gigabits/hour = 9.6(60X60) = 2.6Mbps
Tivo recorded - best quality - 2.5GB/hour or 20 Gigabits/hour = 5.5Mbps
PC-Based - DVD quality - 3GB to 1GB/hour or 24 Gigabits to 8Gigabits/hour = (6.6Mbps to 2Mbps)
- So anything less that Tivo "Best Quality" should transfer without having to pause.
How best to maximize your ability to transfer a file and watch at the same time without Tivo having to pause:
- Unless you intend to eventually move a Tivo recorded program to DVD, using Tivo set up, change the default program recording quality to "Medium."
- Always transfer any file recorded in quality above Tivo "High" in advance of actually wanting to view it.
- Never try to transfer and immediately watch a file if the source of the transfer file Tivo is in the process of actually recording the current channel.
- If you use PC-based servers, start Tivo Desktop, go to Services, then Server Properties, then Performance and set the Cache option to maximum and Activity Level to Medium.
- If you use PC-based servers, keep the hard drive holding Tivo files defragged.
- If you must transfer a file and attempt to watch it in real time, at least let the file transfer for several minutes before beginning to play it, giving Tivo a buffer that it might be able to keep filled ahead of you watching.