LinX - A simple Linpack interface

[autox]

I have a i7 DO clocked to 4ghz using win7 x64.
Here are a few problems/questions I have.

1) I get variable Gflop when I run Linx. It would always be consistant during the entire run, but would differ from one session to the next. The funny thing is that when th Gflop is lower, my temps don't heat up as much. Before you say that my CPU is throttling, i have i7 turbo loaded and noticed no drop in the multiplier. This also occured when I was on a q9550.

2) I get lower Gflop (by about 9), when I have HT on vs. Off. Any idea why?

[sniggle]

2) I get lower Gflop (by about 9), when I have HT on vs. Off. Any idea why?

From the official release notes:

Known Limitations
1. Intel(R) Optimized LINPACK Benchmark is threaded to effectively use multiple processors.
Therefore, in MP systems, best performance will be obtained with hyperthreading turned off.
This insures that the operating system assigns threads to physical processors only.

Everyone seems to get approximately 20% worse performance with HT enabled in Linpack.

I have HT disabled always because:

1) Various benchmarks show that in general HT only helps encoding/rendering applications and hinders performance in many other things.
2) When all 8 logical CPU's are maxed it really feels like Windows is slower to respond in general than when HT is disabled and all 4 physical CPU's are maxed.
3) My CPU runs cooler and I get a higher overclock

[sukebe]

This is what I'm talking about. The amount of stress (Gflop) is veriable from one session to the next.

That's right, when it produces higher Gflop numbers it's putting more stress therefore shows instabilities quicker... in my case the gflops can vary from 48 to 54 in different sessions with identical settings, which means it can take about 30 minutes more to get an error when gflops are at the lowest (compared to the highest)...

@sniggle
Interesting stuff, we've also seen many single-threaded benchmarks perform better with HT off. What i wonder now is if games can perform better without HT, considering that it's probably most demanding apps on i7 rigs nowadays

[sniggle]

@sniggle
Interesting stuff, we've also seen many single-threaded benchmarks perform better with HT off. What i wonder now is if games can perform better without HT, considering that it's probably most demanding apps on i7 rigs nowadays

From what I've seen games generally do better with it off. There was a very comprehensive benchmark somewhere but I don't have the link, but here's something I found with a quick search: http://www.bit-tech.net/hardware/cpu...-cpu-review/10

Bottom line is that unless you're running a video crunching box you're probably better off with HT off.