64 bit or 32 bit?

[gadders]

Can anyone tell me.. what are the advantages of getting a AMD Athlon64 3200 over a 32 bit 3200 +? Are there any disadvantages?

Also anyone know of a good mobo for a 64 bit AMD?

 

[pitsi]

The A64 3200+ has no disadvantages over an AXP 3200+, except maybe the price, but it is a superior chip in every aspect!

Do you absolutely need bo built now? If you could wait until the end of March, AMD will release its new CPUs for both S754 and the newly introduced S939. If you can afford a S939 (nobody really knows what's their price going to be), then that would be the best choice, as far as both performance and future upgradability goes. On the other hand if budget IS a problem, then you can buy now an A64 3200+ which is still a very good processor (or maybe wait a week because I think there is a price drop coming from AMD within the next week).

A good mobo would be the Asus K8V Deluxe. Whatever you do, make sure you buy a mobo using the K8T800 chipset and not the Nforce 3. On the other hand, new chipsets are coming out as well along with the new processors, so as I said before, if your budget is not tight, maybe waiting for 1 1/2 month would be the best choice.

 

[gadders]

Budget is a bit of an issue.... I will currently be paying £200 ($370) for the 64 bit AMD 3200. I can't really afford much more than that. I guess these new chips will empty my wallet?

How does the Abit KV8-MAX3 mobo compare to the Asus you mentioned?

 

[P4Man]

There is no point in getting a XP3200+ these days, unless you have a socket A board you must hang on it. A A64 3000+ wouldnt be more expensive, and vastly superior to the AXP.

On the 64 bit question, let me paste below what I wrote elsewhere regarding potential performance gains running 64 bit software :

Well, let's see. first of all, I want to stress that performance as such is *not* the biggest advantage of 64 bit computing. Its the flat memory addressing, more than 2 GB addres space for your apps, no more fragmented virtual memory leaving you with just a couple hundreds of megabytes of continues memory.

That being said, a 64 bit cpu can be faster in some cases, especially the K8. First off all, there is like you mentioned, apps that require math on integers bigger than 32 bit. A 64 bit cpu can crunch these in theory up to 4x faster (in the case of 64 bit multiply which can done at once, instead of in 4 steps like on a 32 bit cpu). However, these apps are rare: mostly encryption, mathematical/scientific apps or simulations. not something you'd run on a daily basis (unless perhaps those Keygen cracks .

Then there is the memory addressing issue; a 64 bit app under a 64 bit OS can access all of its memory directly, whereas on x86, a process is limited to 2 or 3 GB period. Hard to put a performance estimate on this, but if an app requires more than what is available, it should launch serveral process and the OS is forced to use PAE and bankswitching crap that is slow as hell and a PITA to develo for. I can't give hard numbers on this, but I would guess memory access could be as much as 5x slower using PAE and passing data from one process to the other. Not to mention, certain apps just can't be programmed around this at all. This will be most apparent in server apps (ERP, Databases, etc,..) and is the reason every other server ISA except x86 has moved to 64 bit ages ago. On the desktop this will be less apparant, since no desktop apps that I am aware off support PAE or /3GB in the first place. The difference will not be performance, but rather: it will work instread of not work. (think photoshop using huge images, and other memory hogs)

Then there are some specific advantages to AMD64. First of all, AMD extended the register set from 8 to 16 (of those, 5 I think are true general purpose registers, so the real increase is from 5 to 15). depending on the code, I would guess this might give you a ~5-10% performance boost.

AMD also extended SSE2 with 8 additional 128 bit FP registers. SSE2 performance therefore should be noticeably better under AMD64 in 64 bit long mode than in legacy 32 bit mode. I don't dare give an estimate though.. but this could have a noticeable impact on SSE2 dependant code (games, 3D rendering, encoding,..).

Lastly, I expect a speedup because of K8 specific compilation optimizations. Currently, most software is optimized for a wide range of cpu's, going from P2/3 to P4, Athlon, A64, etc.. Code compiled for AMD64 should not enable switches to remain compatible with (or optimized for) older cpu's, since K8 is the only AMD64 cpu anyway. I would bet currently most new applications are compiled with the P4 as performance target, not the K7 (which is logical given the marketshare). For 64 bit code, this won't be true anymore, performance optimization target will be the K8, and this alone might lead to more significant speedups than everything mentioned above, even though it has nothing to do with "64 bit" as such. Its just the benefit of the market leader (in this case, the prettty small 64 bit x86 market).

But AMD64 also has its drawbacks, not everything will speed up. Two things: when you use a 64 bit OS, and if you run an app that doesnt need 64-bit data you can use the old 32-bit instructions just fine and only use 64-bit ones as necessary. However, a pointer is always going to be 64-bits in AMD64 long mode, so some applications might take a slight performance hit because of the extra strain on the memory bus caused by loading 64-bits for every pointer instead of 32. I would expect the extra registers to offset this possible disadvantage, but quick & dirty recompiles could actually give you a minor performance hit, instead of an advantage.

A second disadvantage is the fact that ICC (intel compiler) doesnt support AMD64 (yet ?). ICC is probably the compiler that generates the fastest x86 code. It is not widely used except for "benchmark software" and of course SPEC, but some cpu intensive apps (think 3D render cores, divx codecs, maybe even GPU drivers,..etc) might well be compiled with ICC because of the performance. Porting to AMD64 will require using other compilers (Microsoft, GCC, Portland, ..) which might not give you as fast binaries. Especially SPEC (where ICC shines) scores will be affected, but some often used benchmark programs might take a hit as well. Your average game OTOH, is not likely to have been compiled with ICC.

Now, you where wondering, what will this give me for "my apps" ? the answer is: I don't know. I am not expecting leaps and bounds, even though I just saw some results under XP 64 that where just incredible (like more than double the performance using DivX). Overall, I am prudent, and do not expect more than ~10%. In same cases, I even expect a small loss of performance, while a few other specific programs might give spectacular increases. For gaming, I doubt we will see spectacular increases in FPS, but I firmly expect future games to enable you to select higher details, bigger maps, etc on a 64 bit CPU/OS. Compare it to DX8 verus DX9; not really faster as such, but more eye candy and more flexibility for developpers.

Add to that, the possbility of running large apps or loading huge datasets that exceed what a 32 bit cpu can supply (if you are running 64 bit windows). Which is not 4 GB, not 2 GB, but in reality, often ~1GB of contigeous memory.

Add to the that the fact you'll basically need a 64 bit CPU and OS to have >256 or at least >512 MB videocards under windows (32 bit windows maps the GPU memory twice in the upper 2 GB range) or you'll be *really* memory starved.

= The views stated herein are my personal views, and not necessarily the views of my wife. =

 

[redface]

by an nforce2 board and XP2500+ with a good retail CPU cooler and PC3200 DDR Rams. OC the XP to 3200+ by increasing FSB from 333 to 400. You will save a lot of money while you waiting for 64bit windows/linux/apps to mature in late 2005. In the mean time, you can save money for much better 64bit capable CPUs at 2006.

A fine day!

 

[gadders]

I currently have a XP 3000+, with a matsonic mobo which has the VIA KT-400 chipset. Is the 3000+ overclockable? I've never o/c'd a CPU before.

I guess the mobo is my first problem. I was looking at the Abit NF7.

I was told by my local retailer to upgrade from a 3000+ to a 3200+ as my PC3200 memory is to fast for my CPU. He said this would reduce my performance by 10% so my options were upgrade CPU or downgrade memory.

So do you think I should stick with my CPU and upgrade mobo? I was also looking at a thermalright SP-97 is this a good choice.

Arghh confusion. I also have temp probs. My CPU is sitting idle at 60 degrees. Will this have harmed the CPU? Any suggestions on a new case and PSU?

 

[pitsi]

If you currently have an XP 3000+, trust me when I say that there is absolutely no point for you to upgrade! As far as I understand, you do not use your computer for any specific specialized tasks that need even that extra bit of performance, but you are an average user instead. Keep your system for as long as you can (until the end of the year maybe?). By then, you will have more money to spend for a new system, and also your options won't be as confused as they are now. Also, why would you even consider an upgrade from a 3000+ XP to a 3200+ XP? There is no way you could tell the difference in performance except in benchmarking tests.

The only thing you might wanna look is that temps of yours, since they are a little high. My target, even with an overclocked Athlon XP, is to never exceed 50C under load.

Two excellent cases are the Antec P160 and the Coolermaster Wavemaster. Also, a great CPU is the Antec TruePower 430w. If you want something cheaper without sacrificing quality, you could also opt for the Fortron 400w PSU.

 

[gadders]

not even my motherboard? Matsonic with via chipset is one of the worst i'm told especially for o/cing. I mainly use mine for games...

 

[pitsi]

I'd say that if you don't have any problems with your current setup, then not even your mobo! If you absolutely need to spend $100 (you know what I mean!), then you could get 512MB more memory. That should give you a good performance boost (unless you already use 1GB, I don't know!). Btw yes, your board is probably the worst, especially when it comes to oc, BUT you are already at ~2.1GHz with that 3000+ and the best you could get from a system built especially for overclocking, would probably be 2.2GHz. Not a big difference there, as you can see!

As I said before, postpone your upgrade until the end of this year and then we can upgrade together

 

[P4Man]

You don't even need to overclock with a 3000+. It should be plenty fast for any game out now, or soon to be released. if you crave more speed for your games, your money is much better invested in a bettter videocard. What do you have now ?

= The views stated herein are my personal views, and not necessarily the views of my wife. =

 

[endyen]

Changing your chip and mobo because your ram is rated to run at higher speed is like changing your motor and transmision because your tires are rated for higher speed. The most gain you will get per $ would be on a better video card. If you already own a Radeon 9800XT or pro give the money to a charity and save the tax deduction for when you rally do need new parts.