I normally don't spend too much time in this Forum (time limitations), but I happened to see the subject. I think its OK to put this sort of question (e.g., hardware advice) in the Tech forum, where it has a good chance of being spotted by those it can help & those that might be technically inclined.

If your post is accurate about the Speed ratings and the cache and price differential, then in fact they are not both San Diego. The 3800 is the Venice. If it is a 130nm 3800+ CPU, then it is a Newcastle core.

The key in deciding is in how you will use it. If you run processes like MP3 creation or video editing or DVD compression, then choose the 3800. That's because the core runs at 2400, vs 2200 for the 3700. The dominant feature is speed, not cache size. For other software, the choice is murky, so I will hit some of the tech details.

Both chips are Socket 939 & have 40-bit physical addresses, 48-bit virtual addresses, 16 total 64-bit integer registers, 16 total 128-bit SSE/SSE2/SSE3 registers. And more importantly for gamers, both have a low-latency integrated DDR memory controller which supports PC3200, PC2700, PC2100 or PC1600 DDR SDRAM and unbuffered DIMMs, with up to 6.4 GB/s memory bandwidth. Coupled with HT, you get one 16-bit link up to 2000MHz, which will give up to 8 GB/s HT I/O bandwidth and 14.4 GB/s total processor-to-system bandwidth. This is a good thing in RTW and Battlefield2, etc. Newcastle (Socket 939) and Clawhammer (Socket 754) cores cannot match this.

About cache that you mentioned, both have and on-chip cache with 64KB Level 1 instruction cache and 64KB Level 1 data cache. The difference is that the San Diego has 1MB of Level 2 Cache, but runs at 2200MHz core CPU speed. The Venice (the 3800+) has 512KB Level 2 Cache, and runs almost 10% faster core speed, at 2400 MHz. This is more important in CPU-limited games like RTW, and hence why I would choose it.

Note: Given an option, stay away from the older Clawhammer 3700+ (2.4GHz) and Newcastle 3800+ (you can ID both by the 130nm die process). Also stay away from Dual Core (Manchester) 3800+ (2.0 GHz core) for now.

The next main question to ask yourself is financial. If it is (saving max money), choose the 3700+. If it is not, then choose neither & get the FX57 which is absolutely without peer right now in gaming... but at ~1,000 USD, its pricy. On the other hand, if you can afford the extra quid differential, then get the 3800+

BOTTOM LINE: Based on taking the context of your post, the choice is the 3800+, easily.

In America, today's mail order prices are:
3700+ (2.2GHz, 1MB L2 Cache) San Diego: $221
3800+ (2.4GHz, 512MB L2Cache) Venice: $283

To run your system well, be sure to look at some more technical detail from AMD,
here.

Good shopping!

EDIT: Holy handgrenades, I got the 3700 and 3800 reversed in Paragraph #3! Its fixed now!

[This message has been edited by Wartrain (edited 12-10-2005 @ 08:35 PM).]

I shoud have added something else... If you actually see a San Diego core CPU in that price range with 1MB of L2 cache and 2.4 GHz, then you will have the model rated as "4000+".

In fact, I would recommend this one, since the additional price is so small... then you have the San Diego core (which is the same core as the FX-55 and FX-57), running at 2.4GHz, and with 1MB of L2 cache. The additional cost is about $50, at $334 today. But if finances are an issue, then the $283 Venice (2.4 GHz/512KB L2) is just fine, and you likely will not see much measurable gameplay difference.

Hi, yeah it is a Venice AMD Athlon 64 3800 512KB L2 Cache sorry.

I want it for gaming. It was just the 3700 having a larger cache thta got me thinking. but as you said, the 3800 is about 10% faster.

My mum went "Maybe" which means yeah, she will spend £200, os she will get the 3800.

I wish I could get the FX57, but im gonna overclock it to the FX57 clock speed.

What is your Motherboard & graphic card?

I plan to revamp my computer with a new motherboard, CPU, better RAM and a gaming case and some other stuff...

But I know I need a motherbaord that supports 939 pin Athlons.

I just look on ebuyer.co.uk and see what mobo best suits me.

My graphics card is a AGP ATI Radeon x700le

Does AGP have a future? Or is it gradually turning PCI-E, in whihc case can you get a mobo with BOTH AGP 8x and PCI-E ? I dont plan to upgrade gfx anytime soon.

Yes, the future is PCIe for techical reasons that result in better performance. However, AGP is not dead by a long shot. If you have the choice in making a new system PCIe would be the card I would buy.

It is my opinion, based on the history of PC 'dual' hardware boards that driver & performance are rearely as good and stable as single-hardware boards deliver. That means that if you want to keep you card (and it sounds perfectly fine), then just get a mature AGP board. In a year or two, you will either upgrade or sell off your hardware, and get new stuff, including a new video card which will likely be PCIe. Possibly dual PCIe (for hardcore gamers, very likely dual PCIe).

check out the Tower I might buy: http://www.ebuyer.com/customer/products/index.html?action=c2hvd19wcm9kdWN0X292ZXJ2aWV3&product_uid=100822

I looked at it in more detail here:
http://aspireusa.net/product.php?pid=153&xcSID=87bd43459c784e0eb32f871a93e06feb

I have never used or seen it in person, but it looks like a good case, and the attention to detail is also good. It has no PS, which is a plus for a real gamer, who will add a good PS anyway. And well, that design looks great, too .

Okay so to sum it all up: 3800 Venice is faster and better than a 3700 San Diego, for gaming.

Yes. But... I like the Kobayashi Maru solution. For ~$50 more, get the AMD Athlon 4000+ (single San Diego Core). But if pressed for the 3800 or the 3700, I would borrow $50 and get the 4000.

I'm not at all going to encourage anyone who is not pretty confident with hardware, but if I had that chip (I don't), I would use some good RAM, and take it straight to 2.6GHz, with a good air cooler like the Zahlman 120. This San Diego core is very good. The Venice is too, but SD is quite a bit better, especially in terms of performance headroom.

But at the stock 4000+, it is 100% worth $50. You cannot get 8%+ systemwide improvement so cheap unless you spend much more (but not as much as the X2 4800) and go dual-CPU (big note -- that's dual CPU, not dual core!).

So its a definite yes. But....get.the.4000.if.you.can.

God dammit! My mum told me today that £200 is too much!! And she wont get me a CPU becuase she doesnt think its worth it, just becuase she doesn't like computers, she thinks its a waste of money, she doesn't even know what a damn CPU is. ARGH...

Now all my plans are ruined, unless I can convince her.

On the bright side, if there is a delay, CPUs & parts will only get cheaper and faster, and you can buy more with less .

I actually was faced with this problem a bit ago. I decided to get the 3700+ and over clock it a bit to get to the 3800's clock speed. The extra cache size is nice.

If you know what your're doing, esp. with cooling, you can take the 3700 up even more. The San Diego actually does have a lot of headroom. But your RAM will need to cope, too.

Note: again, most users should not go try and overclock unless you are well-versed in OCing (you can google to help learn)... don't rush out and try it because you see me and a few others blathering about it!!

Well if i ca get the 3700 and OC it, I am gonna buy an Arctic 64 cooler, then I'm OK, I eman Upgrading from a 2.2GHz Celeron on a crappy Motherboard to a very good Motherboard with an AMD 3500 (my original plan) is a HUGE step, apparently, so getting a 3700 is pushing it a bit further. I suppose I can live without a 3800...

The fastest CPU I have ever used is a 2.79GHz Pentium 4 I think

Given your finances, if you still buy a CPU, then I change my recommendation of before, as the financial issue becomes a dominant factor. Get the 3700+, and save $50. I doubt you would ever be able to tell the 3700 from the 3800 in normal use, without a benchmark helping you. Basically, you should probably make do with whatever you have until your finacial issues are in order. "Fast" computers are a luxury. And there will always be a faster one next year...