Ubuntu 32-bit, 32-bit PAE, 64-bit Benchmarks

[energyman]

no, in memery increased by 25% too, if I remember correctly.

it will be roughly the same. Since data and commands are seperated in L1 at least data will not suffer.

Also, while you don't have L3 with Athlon II you will get a bigger L2 (except if you are coming from an old X2 6000). 1mb/core is not too bad. More than most old X2s. And the Athlon II Regor core is faster on the same clock than the old Kuma or Windsor/Brisbane. So.. don't worry too much.

[Drago]

AFAIR when I switched on disk usage increased by ~25%. RAM usage increased by roughly the same amount.

But that was many many years ago

What do you mean "increased by same amount" ... 100% increase?
However, I am not concerned about system RAM usage. I am concerned about L1/L2 cache usage on my future Athlon II.

[cl333r]

We're demanding Phoronix to provide a i686 benchmark too! )
Fedora 12 is i686!

[energyman]

AFAIR when I switched on disk usage increased by ~25%. RAM usage increased by roughly the same amount.

But that was many many years ago

[tettamanti]

I also think that this huge difference is due to i486, rather than i686 optimization. Does anyone knows how 64-bit programs impact CPU on-die cache memory. Doesn't addresses in it, eat twice as much, than 32-bit code, effectively half usable cache size. How this affects smaller CPUs, like Athlon II for example?

There's certainly an increased code size and memory usage, but keep in mind that the default operand size is still 32bit. Addresses are 64bit, so pointers and function calls takes twice the memory, but overall the memory footprint isn't doubled.
I haven't seen a real analysis on this, so I can't give you numbers...

[energyman]

It would be really, really great if someone could test Gentoo x86
vs Gentoo x64 and show whether there are any gains to achieve.
Both with SSE2/SSE3, gcc optimizations and so on. Phoronix is
just full of 'Ubuntu this, Ubuntu that' - well Ubuntu is just one
member of a big GNU/Linux family, give some love to other distros
as well.

"So pretty please... with sugar on top. Clean the f-car."
Winston Wolf

do it yourself :P

[energyman]

I also think that this huge difference is due to i486, rather than i686 optimization. Does anyone knows how 64-bit programs impact CPU on-die cache memory. Doesn't addresses in it, eat twice as much, than 32-bit code, effectively half usable cache size. How this affects smaller CPUs, like Athlon II for example?

not everything doubles. Only integers and pointers. Everything else has the same size. So amd64 code is a bit bigger but not very much.

[energyman]

some time ago I found that some of the PTS tests compile with no optimization at all on 64bit but at least set a sensible march on 32bit.
If that is still true and some of tests afflicted by this used in the test, the results could be even more one sided.

That said, while computing tests should show a lead for 64bit because of the additional registers and the greater 'length', it doesn't make a lot of sense when disk bound tests are faster too.

Something might be rotten in the state of Denmark.

[n0nsense]

It would be really, really great if someone could test Gentoo x86
vs Gentoo x64 and show whether there are any gains to achieve.
Both with SSE2/SSE3, gcc optimizations and so on. Phoronix is
just full of 'Ubuntu this, Ubuntu that' - well Ubuntu is just one
member of a big GNU/Linux family, give some love to other distros
as well.

"So pretty please... with sugar on top. Clean the f-car."
Winston Wolf

There is a new writer at anand, he using Arch for reviews.
And I totally agree with "'Ubuntu this, Ubuntu that'.
Michael promised Sabayon review this week.

[clavko]

It would be really, really great if someone could test Gentoo x86
vs Gentoo x64 and show whether there are any gains to achieve.
Both with SSE2/SSE3, gcc optimizations and so on. Phoronix is
just full of 'Ubuntu this, Ubuntu that' - well Ubuntu is just one
member of a big GNU/Linux family, give some love to other distros
as well.

"So pretty please... with sugar on top. Clean the f-car."
Winston Wolf