Jump to content

X2 3800 vs 3700 San Diego


espn2829

Recommended Posts

Tweak50:

 

Wow, I'm so glad you actually read that article.

 

I never said HT was a good technology, or even compared it to duals. Please read my origional post.

 

What I said/meant was that HT was intended to use multi threaded apps, amongst other objectives. And programmers/developers hung it out to dry in that sense, not writing for it. I would be surprised to find out that that was the first time a technology or instruction set was castrated by improper developer support, or it didn't come fast enough.

 

I like duals. But for right now, they can't make up the diff they lose in gaming, by lower average mhz. Anyone that tells you it for sure will or when, is trying to read the future. Your completely in the hands of programmers/developers. Even when it all gets sorted out( and I personnaly believe it will, just growing pains), I have no idea if it will make up a 200mhz diff. I guess none of us will, until well after we have bought our cpu's, when the new games come out.

 

PS All statements are reffering to gaming! Please don't anyone say "he thinks dual cores can't multi-task, what an idiot!", that is NOT what I said please read what I said twice and fully before you jump on me. Tweak50, I hope we can both learn more from this correspondance. And for god's sake man, I've dealt with many sales reps( albeit from a different industry), they are the devil man! You have to be very talented to get the full truth from them.

Share this post


Link to post
Share on other sites

Single non-hyperthreaded cores, Single hyperthreaded cores, dual core CPUs, and systems with multiple CPU's can ALL run multi-threaded applications.

 

Multi-threaded operating systems go back decades. Pull up task manager in Windows XP, switch to the performance tab, and notice the number of threads running on your system. I've got 536 right now. This shows that my operating system is running a lot of threads! Now go back to the Processes tab and click View -> Select Columns -> Thread Count. Right now Mozilla (which I'm using as I write this) is using 7 threads. This shows that my app is running a number of threads!

 

Now you guys know that non-hyperthreaded single core CPUs can only execute one instruction at a time. The operating system coordinates context switches which result in these many, many threads each executing for a fraction of a second before the Operating System preempts the thread and gives a turn to another thread.

 

Each time that the Operating System performs a context switch several things must happen. The registers in the CPU and some other stateful information must be saved until the next time this thread gets a timeslice. Then the registers and other stateful information from the thread that will execute next gets restored exactly as it was when the thread was last preempted.

 

One problem to point out is that this context switch is "expensive". A certain amount of processing time goes toward performing this context switch.

 

Dual CPU (and even quad, etc) systems have been around for a long time as well. Such systems literally execute two threads at once. Because your operating system is constantly round-robining to other threads these dual CPU systems must go through context switches just like single CPU systems. The difference is that two threads execute at any given time, which yields twice the total processing power assuming that you've got two threads that are actually that hungry.

 

Now let's go back to single CPU systems. The advent of hyper-threaded cores was something of a novelty. The idea was that we could make a CPU lie to the operating system, claiming that it's really a dual core (or dual CPU) system. The operating system then attempts to keep two threads executing at any given time. However, the hyperthreaded CPU juggles the two threads, performing context switches at the hardware level, and in the end you still only have one executing instruction at the time. Think of a hyperthreaded CPU as a "simulated" multi-core or multi-CPU system. What's the benefit? The context switches between the two active threads are fast and this may help give the illusion that you can perform two CPU-intensive tasks.

 

A dual core CPU can be thought of exactly like a dual CPU system. One of the great benefits of dual core systems though, is better memory sharing between the cores, etc.

 

Are games single threaded? Most are *not*. Let's not say that games are single-threaded and therefore do not take advantage of multi-core systems. It's more accurate to say that games do not yet balance the CPU load across multiple threads. Achieving this in games is harder than it may sound. Many games are written with a traditional game loop which does something like:

 

1 - Process the user's input. How does this change the environment.

2 - Process non-player characters. Move them around, etc.

3 - Start sound streams based on 1,2.

4 - Render a frame.

5 - Goto 1.

 

This is simplistic but the point is how much room for parallism is there versus to what degree must the steps above be handled sequentially. Games will take better advantage of multiple cores / CPUs in the future, if for no other reason than that environments will continue to become more sophisticated in games and one thread might constantly think about the changing environment while other threads process user input, physics calculations, and rendering.

 

This may or may not help the discussion you guys are having here.

Share this post


Link to post
Share on other sites

[G.N.U.]Fragman is right abou the Opterons, I got mine too. Just be wary of the steppings. CABNE is king, CABGE is reportedly garbage, CABYE is pretty good. As always of course not every cpu will apply to this generalization blah blah blah.

 

Contrariedad, thank you for that. There was a few things in there I didn't know( or maybe alot). The only thing I didn't like in there was that you said "Games will take better advantage of multiple cores / CPUs in the future...". That is what I was speaking aginst in my origional post. Its the "will" that bothers me, I agree that it problably will happen, but then you should say "problably".

 

Deveolpers don't have to decide to do anything, programmers won't deffinately succede in their objective. If, when, and how effectively, dual cores take advantage of a game or app is not known, any guess is just that. Again I say I do believe that newer games and apps will take advantage of dual cores, but my beleif does not constitute a fact. And that should be said clearly when it affects someone else's purchaseing decision.

 

But that is a minor quarrel. Good on you for doing your research, and well spoken.

Share this post


Link to post
Share on other sites

Contrariedad, thank you for that. There was a few things in there I didn't know( or maybe alot). The only thing I didn't like in there was that you said "Games will take better advantage of multiple cores / CPUs in the future...". That is what I was speaking aginst in my origional post. Its the "will" that bothers me, I agree that it problably will happen, but then you should say "problably".

 

Deveolpers don't have to decide to do anything, programmers won't deffinately succede in their objective. If, when, and how effectively, dual cores take advantage of a game or app is not known, any guess is just that. Again I say I do believe that newer games and apps will take advantage of dual cores, but my beleif does not constitute a fact. And that should be said clearly when it affects someone else's purchaseing decision.

 

Oh, I agree with your points here.

 

Good on you for doing your research, and well spoken.
Though I'm not a game developer, I am a software developer. I work with threading on a daily basis along with other programming issues. I'm no expert on the subject but hopefully what I shared is helpful.

Share this post


Link to post
Share on other sites

×
×
  • Create New...