confused: Athlon 64 purchase

[deviantchild]

So I may be in the market for a Socket 939 CPU as my K7 MoBo could possibly be dead.
What's the best Athlon 64 I can get outside of the expensive FX and X2 (Dual Core) ranges?
What full specs am I looking for?
Just trying to avoid any nasty surprises such as crippled/unbalanced chips etc.
Any input in order to clear the mud would be greatly appreciated.
TIA,
d3v

 

[Vadi]

AFAIK you can choose between more chache or clockspeed. No mistakes to do.

 

[Tim]

So I may be in the market for a Socket 939 CPU as my K7 MoBo could possibly be dead.
What's the best Athlon 64 I can get outside of the expensive FX and X2 (Dual Core) ranges?
What full specs am I looking for?
Just trying to avoid any nasty surprises such as crippled/unbalanced chips etc.
Any input in order to clear the mud would be greatly appreciated.
TIA,

There are two different cache sizes 512KB and 1MB, but only the relatively expensive 3700+(2.2GHz) and 4000+(2.4GHz) and the very expensive FXs (2.6 and 2.8Ghz) A64-chips has 1MB. The real tasty option is the s939 1xx Opterons even the cheap ones like the 144(1.8Ghz) and 146(2Ghz) has 1MB L2 - they are great overclockers and allows you FX performance at around $150 (maybe a bit more).

The only problem is that availebility of the s939 144 and 146 Opterons are pretty poor.

Anyway even the 512KB cache A64s are very good CPUs (I have an A64 3200+). Here is a short overview:

3000+ 1.8Ghz 512KB L2
3200+ 2.0Ghz 512KB L2
3500+ 2.2Ghz 512KB L2
3700+ 2.2Ghz 1MB L2
3800+ 2.4Ghz 512KB L2
4000+ 2.4Ghz 1MB L2

Opt 144 1.8 Ghz 1MB L2
Opt 146 2.0 Ghz 1MB L2
Opt 148 2.2 Ghz 1MB L2
Opt 150 2.4 Ghz 1MB L2

 

[the maddman]

If you're playing games, clockspeed seems to be more important than the 512k vs. 1meg cache. I'm running a 939pin 3000+ right now, waiting for the dual cores to get a bit cheaper before I upgrade.

I recommend any of the A64's, they really are a step above the Athlon XP. Just get the fastest A64 that's not a rip off and have fun with it.

edit: P.S. Try and make sure you get one of the newer cores (Venice) with SSE3 support. They run nice and cool, and have better memory controllers that can run 400mhz DDR with more modules.

 

[deviantchild]

Thanks a lot, everyone.
I'm not an overclocker these days - system stability is more important to me.
I think I understand the relationship between the families a little bit more since yesterday.
Someone elsewhere mentioned that the higher rated chips of the 64 family, such as the 4K,is essentially a repackaged FX 53.

 

[Azrael]

http://www.monarchcomputer.com/Merchant2/merchant.mv?Screen=PROD&Store_Code=M&Product_Code=120332

No contest. Even the worst will almost always clock to 2.6ghz on stock cooling and be 100% stable. If it's a CABYE 0540 it will almost always go to 2.8 stock @ 1.4 volt and be 100% stable.

 

[deviantchild]

http://www.monarchcomputer.com/Merchant2/merchant.mv?Screen=PROD&Store_Code=M&Product_Code=120332

No contest. Even the worst will almost always clock to 2.6ghz on stock cooling and be 100% stable. If it's a CABYE 0540 it will almost always go to 2.8 stock @ 1.4 volt and be 100% stable.

Right.
Now that I'm confused again.
The current contenders...

AMD Opteron 148 2.2GHz 1Way S939 1MB L2 64Bit
AMD Opteron 165 1.8GHz 1Way S939 2MB L2 64Bit Dual Core
AMD Athlon 64 4000+ 2.4Ghz S939 1MB L2 90nm Soi Stepping E4
AMD Athlon 64 4000+ 2.4GHz S939 1MB L2 130nm
AMD Athlon X2 3800+ 2.0GHz S939 512KB*2 L2 Dual Corehttp://www.techstore.co.uk/detail_67449.html

Any further suggestions?

TIA

 

[Skrying]

The Opteron 148 is a great deal. I'd go with it all the way over any of the other processors unless you feel you're a heavy multi tasker and want dual core.

Either way, I'd choose between the Opteron 148 or 3800+ X2. Cant go wrong with either, A64s are simply amazing CPUs.

 

[the maddman]

From the prices I saw on your links, the Opteron 148 does look like a great deal.

I personally want a dual core, since I'm always multitasking, so I think I'd go with the Opteron 165. But if you want maximum performance in a single app, the 148 sounds like the ticket. I wouldn't pay 50+ for 200mhz.

Whatever you pick, you'll enjoy it! All of those chips are going to be fast.

 

[deviantchild]

That site only really had the best price for the Opteron 165, which is what i was looking at, but they don't have the best prices for all of those.
I do sometimes do quite a bit of multitasking.
The Dual Core and 2MB cache has the 165 over the 148 for me, but how does that bear on the 400MHz trade off in the opposite direction?
I have found the 2.0GHz X2 Dual Core at a very similar price to the Opteron 165 so how does the 2 x 512KB cache compare to that of the 165? and the 200MHz difference between those too.
I'll try to get a better price comparison for all of those tomorrow. But for now, sleep.

Again, thanks for all the input - it's getting interesting.

 

[Tim]

That site only really had the best price for the Opteron 165, which is what i was looking at, but they don't have the best prices for all of those.
I do sometimes do quite a bit of multitasking.
The Dual Core and 2MB cache has the 165 over the 148 for me, but how does that bear on the 400MHz trade off in the opposite direction?

The 148 is about 15% faster on average in single threaded software, but more and more software take advantage multithreading (Ati and NVIDIA has multithreaded drivers now). Also a dual core system feels a bit more responsive than a single core system and the ability to run heavy tasks (like encoding) in background and still be able to play games etc. is nice. All in all I would go for the multicore chip.

I have found the 2.0GHz X2 Dual Core at a very similar price to the Opteron 165 so how does the 2 x 512KB cache compare to that of the 165? and the 200MHz difference between those too?

At stock speeds the X2 3800+ is a bit faster, so if you don't want to overclock it might be a better choice. (also the x2 is availeble, but it is hard to find the 165 in stock anywhere).

 

[Cartoon Corpse]

how are processes allocated over the dual cores? will a large (say a game) automatically get 'all' of one core, while all lesser processes are grouped on the other.

are lesser processes utilizing both cores when no huge game is running?

do you specifically allocate which core you want program x to run on?

xp does all this already?

'parallel' boxes i've used required special versions of OS..

 

[Gubbi]

how are processes allocated over the dual cores? will a large (say a game) automatically get 'all' of one core, while all lesser processes are grouped on the other.

are lesser processes utilizing both cores when no huge game is running?

do you specifically allocate which core you want program x to run on?

xp does all this already?

'parallel' boxes i've used required special versions of OS..

Sadly, the scheduler in XP does what most schedulers do: Try to average the run queues of the processors in the system.

This is bad when you run a single threaded application (like, say, a game) because the game will run for a timeslice (typically 10ms) on one CPU core, then the scheduler will reschedule the proces to the other core, because it's run queue is empty, and the one it has been running on is not, and it tries to average the reques.

So for the next timeslice the application gets to run on the other CPU core, paying a hefty price in cache misses (average load-to-use latency going from ~3 to >20 cycles), because all data are in the primary and secondary caches on the other core.

10ms later it switches back.

This means that you have to set affinity for a program so that it will only run on one core in the system.

A complete pain in the ass.

Cheers

 

[Cartoon Corpse]

what's the command line (i kick my games of on my 1.4Gz from command line, after killing everything else) command option to choose affinity? is there one?

will there be a multicore xp 64 OS coming out before vista? will vista address this?

that sounds like dual core is potential (without tweaking) a major bad idea for single thread games.

 

[Gubbi]

We had a similar discussion here. There's a link to a tool for setting affinity via the command line.

For games that have launchers, like HL2, there's no such luck. I alt-tab out after starting the game, and sets affinity in the task manager. I do this everytime I play CS:S (hence my PITA comment).

Dual core are great for eveything else.

Cheers
Gubbi

 

[the maddman]

We had a similar discussion here. There's a link to a tool for setting affinity via the command line.

For games that have launchers, like HL2, there's no such luck. I alt-tab out after starting the game, and sets affinity in the task manager. I do this everytime I play CS:S (hence my PITA comment).

Dual core are great for eveything else.

Cheers
Gubbi

Wow, I hope MS is working on the XP scheduler. With the explosion of dual core processors, they should be handling heavy single threaded apps better. I haven't had a SMP rig since I got sold of my dual AthlonMP 2000+, and I ran Linux on that mostly.

 

[KimB]

Sadly, the scheduler in XP does what most schedulers do: Try to average the run queues of the processors in the system.

This is bad when you run a single threaded application (like, say, a game) because the game will run for a timeslice (typically 10ms) on one CPU core, then the scheduler will reschedule the proces to the other core, because it's run queue is empty, and the one it has been running on is not, and it tries to average the reques.

Er, this doesn't seem to be the case on my system. It seems that when I run a single-threaded game on my X2, one core is almost continually hammerred, while the other lies nearly dormant, for a fairly extended period of time (a few seconds).

Now, I have seen programs that swap back and forth frequently (3DMark05 seems to do this), but I'm not sure as to the exact reason why some swap between the cores, whereas most just stick to one.

That said, I don't think there should be much of a performance hit from switching tasks between the CPU's on the Athlon X2, due to the existence of a high-bandwidth dedicated lane between the two CPU's.

 

[the maddman]

Er, this doesn't seem to be the case on my system. It seems that when I run a single-threaded game on my X2, one core is almost continually hammerred, while the other lies nearly dormant, for a fairly extended period of time (a few seconds).

Now, I have seen programs that swap back and forth frequently (3DMark05 seems to do this), but I'm not sure as to the exact reason why some swap between the cores, whereas most just stick to one.

That said, I don't think there should be much of a performance hit from switching tasks between the CPU's on the Athlon X2, due to the existence of a high-bandwidth dedicated lane between the two CPU's.

Still moving a thread from one core means the X2 has to copy data from one L2 cache to the other or just flush it. If a process is ping-ponging it's less efficient than if it just sticks to one core.

Hopefully, what you are seeing is programs automatically setting affinities as the developers get used to the idea of dual core. Having one core at 100% is better than seeing the two at 50%.

 

[KimB]

Hopefully, what you are seeing is programs automatically setting affinities as the developers get used to the idea of dual core. Having one core at 100% is better than seeing the two at 50%.

Well, no, I'm just talking about old programs that use up lots of CPU cycles. I really don't know what's causing it, but this seems to be the case for most software I run.

 

[the maddman]

Well, no, I'm just talking about old programs that use up lots of CPU cycles. I really don't know what's causing it, but this seems to be the case for most software I run.

That's a good sign. Are you running XP SP2? Perhaps MS has updated the scheduler.