[ZmaN]

I read in a Tom's Hardware review that Hyper threading DECREAASED performanced when it was enabled, but performance was increased when it was turned off....  is this true???


My specs are below...  Would it help any (framerate-wise) if I disabled hyper threading in my bios????

[StratComm]

It depends on the applications that you are running.  Most of those things are running benchmarks that are usually either single-threaded or cache-thrashing, neither of which is exactly representative of a normal computer workload.  Of course, when running games, you are running more or less single threaded apps in most cases so perfomance won't be as good.  I'm not too well versed on Intel's implimentation of multithreading, but in general, for a typical PC, it's not a bad thing.

[WMCoolmon]

If you alt-tab or play music in the background it can help increase performance.

[Scuddie]

HT is designed specifically for multitasking, and it sometimes improves stability.  It does this by splitting one CPU into two or more logical ones.  The idea behind this is that when two or more programs are running, the CPU load of one program is nearly independant of the other.  For example, i have known people to render videos and play CPU intensive games at the same time without one program hampering the other.  Both programs run about 60% possible speed, but that number is consistent.  In theory, an HT enabled PC with the OS running at logical CPU 0, and all programs running at logical CPU 1+, the PC will not crash due to infinite loop.  However, these circumstances matter not when a person is running only one application.  The system will usually be sluggish because of the fact that logical CPUs cycles are in waiting, and the clock cycles are essentially wasted.

I hope this clears that up .

[Descenterace]

For true multiprocessing goodness you want something like my Athlon X2 4200.

Windows takes just as long to boot as on an Athlon 3500, but the UI is responsive as soon as it's visible instead of being slowed down by all the startup apps loading in the background.

Plus, I've never seen an antivirus scan run in the background without slowing down FEAR before now.

[aldo_14]

I read in a Tom's Hardware review that Hyper threading DECREAASED performanced when it was enabled, but performance was increased when it was turned off.... is this true???

My specs are below... Would it help any (framerate-wise) if I disabled hyper threading in my bios????

IIRC (for one thing) HT suffers from issues in memory managing threads; from what I remember, whilst it has multiple processing pipelines, the actual memory and memory access controller is shared so you have problems with deadlocking, etc, that wouldn't occur in a true MP system - akin to the prediction problems in any pipeline, except this time across multiple pipelines rather than stages.

What I remember is that HT requires programs to be optimised for it to have any performance gain (I don't know offhand if it's compiler or coding level optimisation), and that without optimisation you have those slowdown problems from unbalanced thread load; (i.e.) such as one of the threads waiting on a memory resource being released by the other thread.

I would suggest that, if you really want to try and improve performance, you simply spend an evening or so benchmarking its performance with HT on and off, for whatever programs you think you could do with improving the performance of.

[ZmaN]

For true multiprocessing goodness you want something like my Athlon X2 4200.

Windows takes just as long to boot as on an Athlon 3500, but the UI is responsive as soon as it's visible instead of being slowed down by all the startup apps loading in the background.

Plus, I've never seen an antivirus scan run in the background without slowing down FEAR before now.

I dont know.,...  I dont think I can afford a decent dual core processor when I build my next computer....  I was thinking an Athlon 64 4000+ for my next one, with an  ATI Xpress 200 Crossfire Chipset...   Is dual core worth it?

EDIT:  Crossfire chipset, not just the Xpress 200

[WMCoolmon]

I'm pretty sure it'd mostly be coding-level, so if/when new games start to shift to more multithreading thanks to more cores, there might be some performance increase from that. But like you said they'll assume that there's a separate cache for the processor if that's what they're optimizing for, which can have (relatively) drastic effects on performance.

[Descenterace]

Don't forget, the OS is running several threads alongside the game too. If nothing else, multicore CPUs are at least capable of dedicating more of a core to the game thread in singlethreaded games.

[Roanoke]

There's little game support for multi-core processors (and the like) at the moment, thought Intel and AMD are 'spose to be working on it.

[Descenterace]

There are fixes to force a game to run on a single core. Most games that have problems with multicore systems are singlethreaded anyway, so confining them to one core wouldn't cause a performance hit.

The problems occur when the game is being switched between cores. Modern games can't rely on Windows for timing, because its clock only ticks once every 50ms or so. Instead, they make use of the CPU's internal status registers to count cycles.
Of course, the two cores maintain their own seperate cycle counts which don't necessarily agree, so the game might take a time fix on core 0, then the OS might move it to core 1 before it takes another time fix. If core 0's cycle count is significantly greater than core 1's, the game gets a negative delta time value and crashes.
The later Unreal games are particularly bad offenders apparently. Other game engines are multicore-aware and lock their timekeeping thread to a single CPU core.

[IceFire]

That whole article on Toms is probably in relation to the article that appeared on Slashdot where they found servers running HT enabled were slower due to overall load and overhead.  For a basic system HT is still providing some benefits.  Ultimately dual core is better....Intel isn't pushing hyperthreading as much anymore.  Its sort of a stopgap added bonus.

[Flipside]

I only found out a couple of days ago that my new computer had hyperthreading. That's how much impact it had, it's also an embarassing indication of how long it's been since I played FS2 properly and not just to look at how a model looks in-game