[mythtv-users] Gentoo 64bit and MythTV completely compatible?

Rod Smith mythtv at rodsbooks.com
Sat Jan 27 19:14:50 UTC 2007

On Saturday 27 January 2007 13:17, Richard Freeman wrote:
> John Drescher wrote:
> >> Is anyone successfully running gentoo 64bit from the gentoo
> >> repositories?
> Been running myth for the better part of year now on 64-bit gentoo with
> no real issues.

When I researched distributions and software for my recent MythTV 
installation, I ran across some posts from ~2 years ago suggesting that 
certain operations (such as transcoding, IIRC) relied on code that had been 
optimized for 32-bit x86, and that such code would run much slower on a full 
64-bit installation. I interpreted this to mean that the software included 
inline 32-bit x86 assembly instructions for x86 platforms, but that on 
x86_64, the compiler would revert to slower C code. I found this quite 
believable because I've run across similar things in the past in other 
software (Ghostscript, IIRC, for one). Unfortunately, I didn't save the 
reference URLs for these discussions, and they tended to be scarce on 
details, so I can't provide anything more specific.

Have such inefficiencies in the 64-bit implementations of these tools been 
eliminated in the intervening time? I'm currently running a 32-bit Ubuntu 
installation on my 64-bit-capable Celeron D system, but if there won't be any 
speed hit to running a 64-bit OS, I'll consider using one when it comes time 
to do software upgrades. Although the speed benefits are small (about 5-20% 
for most programs), x86_64 code can be a little faster than x86 code on the 
same CPU, all other things being equal.

Rod Smith

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