Geminiwave

I was looking at the Sempron processor and some of them are Athlon 64s with the 64bit extension disabled. That got me thinking...isnt it just a matter of getting that old silver pen out and making some modifications to enable them?

what do you guys think? Is it possible?

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Judas

i would enjoythat.... but it would be a severly limited 64 bit cpu...however... nothingl ike running 64 bit programs if you can get it going!

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drakesteakn

i don't think it will be a real modders paradise. but we may be able to unlock some features

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Geminiwave

how would it be limited? They are taking A64s and disabling features. From all of the articles I've read, they are manufactured identically. In fact a large ammount of them will still show up as Athlon XPs or Athlong 64s and still be marked on the Processor itself as one.

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The_Neon_Cowboy

thier not cut down a64's...

It's a cut down barton (1/2 cache) ported/adapted to use multiple pinings, the socket A,754,939 all same core...

you can't turn on whats not there this is a 32bit only cpu! if any thing you might be able to enable the extra cache if it's even there (but it's likely bad...)

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Vampyromaniac

actually, Neon, the socket 754 Sempron are based on the K8, not AthlonXP like the socket A Semprons
they're pretty fast, but No, you won't be able to turn on the 64-bit capability, I'm 99% sure.

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Geminiwave

okay. Well I guess we shall see.

as far as the Athlon XPs->Sepron go, since the cache is still there, just disabled, im guessing it would just be a matter of doing some tricky work with a silver pen.

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Nacht

yea, i thought the sempron was a rebadged athlon xp thoroughbred....but you say that's only the lower end ones?

Geminiwave

they arent even Tbreds. its cut down bartons with half of the L2 cache disabled(so its like a tbred). For awhile at least, they are suppose to still say Athlon XP on the processor and on the CPUID on the computer. There are some BIOS updates for fixes incase the CPUID ends up being Sepron eventually(Though im not sure it ever will)

The A64s show up as Opterons though which is very interesting(maybe they are cut down opterons?)

in any case the ones above the 3100+ proc are all a64s with disabled 64bit extensions. Thats the only difference. Since those extensions arent even used, that could be a VERY good processor to get(depending on the price)

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No_Style

If it were a cutdown A64.. Then the AMD Sempron would own so much. But it isn't~ They would also need the on die memory controller

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Vampyromaniac

No_Style, the Sempron 3100+ is indeed a Athlon 64 core, with 256k cache and 64-bit capability disabled.
I don't understand why you guys keep saying it isn't

Once again, guys... there are 2 versions of the Sempron chips: Socket A, and Socket 754.
The Socket A Sempron is merely a Thoroughbred chip: 266 MHz FSB, 256k cache, same die size as the original Thoroughbred.
The Socket 754 Sempron have a A64 core, with 256k cache, on-die memory controller, and every onther enhancement the K8 came with, Except no x86-64.

I wonder where you guys are getting your info

Also, such things as turning on the 64-bit, or extra cache, will not be do-able with just a silver pen. Those are inside the die, they don't have anything to do with bridges that are out on the substrate.

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pr0digal jenius

you can always write your own bios hacks and such with a silver pen before you program them

Geminiwave

Hey I knew the 754s were A64s.

as far as the x86-64 extensions go, it was just a thought. I suppose time will tell. btw I'm quite sure that the other chips are Bartons with disabled caches. I know that the article i read on THG said that at least some of them had Barton CPUIDs. I would assume that means they just disabled half the cache(thats what they do with Celeron processors. Many are just normal Pentium 4-As with half their cache disabled.

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Vampyromaniac

I know you knew about the A64's. as far as the Barton question, software isn't perfect, Bartons never ran at 266MHz FSB, and if you look at pictures of the Socket-A Sempron, you'll see the die size is identical to Thoroughbred, whereas Barton has a longer, thinner die.

I just checked THG and they were saying it's Thoroughbred too

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No_Style

Well, if I knew about the two different cores of a Sempron... But I didn't. I thought they were all Thoroughbreds. I hadn't encountered Sempron 754.. since budget processors aren't my thing

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Geminiwave

Are they even out yet? Im pretty sure they havent hit the shelves.

I may very well be tempted to go the sempron route if 64bit doesnt get accepted alittle better.

edit: OH MY GOD!! ON NEWEGG.COM THEY ARE THORTONS!!! AHAHAHAHAH THATS GREAT!!

So far there arent any A64 versions on it though.

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No_Style

The question is... Why?

Why would a budget user, want to get a Sempron based on socket 754? Budget users would want to suit their budget processor with a budget mobo and so far nothing Socket 754 wise can really be considered a "budget" mobo. If I were you, GeminiWave, I'd just go for the A64.

Not for the 64-bit, but for the fact that you're not getting a butchered chip

These lines from TechReport says it best:

"However, AMD's marketing folks have lobotomized the Athlon 64 "Newcastle" core in order to keep Sempron from beating up on its big brother. Like the Socket A Sempron, the K8 version has only 256K of L2 cache, and it can't do 64-bit addressing. By virtue of its Socket 754 pinout, the Sempron can only converse with a single channel of DDR400 memory at once. Also, the Socket 754 Sempron's HyperTransport link officially peaks out at 1.6GHz, while newer Athlon 64s support 2GHz HyperTransport speeds."

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The_Neon_Cowboy

yea but the 333 fsb is a dead give away

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Vampyromaniac

fair enough
Newegg is not always accurate. The "Thorton" die looked exactly like a Barton die (of course, since it is a Barton with half the cache disabled). Looking at a picture of a Socket-A Sempron, you see it's a Thoroughbred die, not long and thin like a Barton or "Thorton".
Well, I guess it depends on what you mean by "budget user". The last I heard, the expected 754-Sempron3100 price was going to be ~$125.

Why not buy a 754-Sempron? Sure, it might sound like a bad chip if you hear people call it butchered or lobotomized. But when it comes down to it in 32-bit, there is only 1 difference between the socket754 Sempron and the socket754 Athlon64: half the cache! This may sound bad at first, but after testing, it is very apparent that the A64 doesn't not need cache say, nearly as badly as the P4 does.

So, it has half the cache. What does that translate to? The 754-Sempron is only slightly slower than the Athlon 64 in most tasks, and in others, the difference is negligible. If you can get a chip that gives you over 95% of the performance of the Athlon64, while costing 20% less, I don't think it's a bad choice for the more price-conscious among us. And I certainly wouldn't call that a crippled chip.

What I still want to see is a comparison of the Sempron3100 versus a P4-2800/3000, but everyone seems to want to review it against Celerons (which it of course leaves in the dust).

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Vampyromaniac

right, the socket-A Sempron's FSB is at 266MHz, and Barton at 333 (or 400).

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Geminiwave

266mhz fsb? sounds like good overclocking to me *grin* i cant wait to get my hands on one now.

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The_Neon_Cowboy

right in one ear and out the other

http://www.newegg.com/app/viewproduc...104-211&DEPA=0

AMD Sempron 2500+ 1.750GHz, Socket A Processor - Retail

Model# SDA2500BOX Item # N82E16819104211Specifications:
Model: AMD Sempron
Core: Thorton
Operating Frequency: 1.750GHz
FSB: 333MHz [color=red]<---------------------------
[/color]Cache: L1/64K+64K; L2/ 256KB
Voltage: 1.65V
Process:0.13Micron
Socket: Socket A
Multimedia Instruction: MMX, SSE, 3DNOW!, 3DNOW!+
Packaging: Retail (Box with Heatsink and fan)


please note it cheaper to get a barton 3200+ then semptron 2800+, cheaper to get a barton 2500+ then to get a sempton 2500+...

the semtpron is clocked lower/ has less cache and coust more then thier barton brothers?

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HawK

think they are all listed here:
http://tech-report.com/reviews/2004q...n/index.x?pg=2

Vampyromaniac

can't blame me if you don't explain what you're referring to I thought you were talking about the Barton

Anyway, you're right. I don't know why I thought the Semprons were 266 . . . maybe looking at the wrong side of a chart somewhere lol. So they are Thoroughbreds with 333 FSB, like the old xp2600. My mistake!
I don't know why Newegg lists them as Thorton, though. Every picture I've seen, shows a Thoroughbred die, not to mention the reviews say so too.

brilliant move by AMD eh?

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The_Neon_Cowboy

i dunno its rather goofy... retailers see that it's new and aprently adding a terrif becouse it new but it's a value/low price line they don't seem to under stand lol

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Geminiwave

AMD might also be trying to raise the price range for them. The Athlon XPs have been dipping rather low in price lately. Granted they are no where near production cost(probably making 1000% profit. yes those are 3 zeros), but even so they arent going to be making the XP anymore. Once the XP is dead, socket A will have nothing else other than the Sempron.

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No_Style

Yeah, the lack of cache will not be a big performance hit, but what about the HyperTransport limit? 1.6 GHz instead of the 2 GHz? Will that affect it much?

Sempron is starting out to be a very misleading bag of processors. I think AMD should have just re-released their Athlon XP line with NewCastle cores and left Semprons to be just 'T-Breds'.. Intel has been refreshing their P4 line with new cores.. AMD should have mimicked the same thing.

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Vampyromaniac

yeah, Sempron is really weird. especially the models numbers, I think it's the stupidest scheme ever.

as for HyperTransport, all socket 754 chips run at 1.6 HTT, including the full Athlon64's. 2.0 was introduced for the socket 939. (that's what Tech-Report meant by "newer Athlon 64's). But, newer chipsets like nForce3 250, when used on 754 boards, are able to OC the HyperTransport. I don't think the extra HTT speed has much effect on performance though, since it's so wide already.

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Nacht

well...definitely wont be buying one of those!

No_Style

Ah ok. Thanks for the clarification, Vampy.

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