Low cost options - Sempron?

nmuntz · Post by **nmuntz** » Mon Mar 07, 2005 3:16 pm

Now that Socket A stuff is becoming scarce and Socket 939 is a little on the pricey side with limited selection (mATX), which Socket 754 Sempron offers the best underclocking and undervolting potential? Or does it at all?

GrahamGarside · Post by **GrahamGarside** » Mon Mar 07, 2005 9:21 pm

None of them offer underclocking as amd removed cool'n'quiet support. So you best bet is the new 2600/2800+ which runs at [email protected], the differance between the two is the 2600+ has 128K of cache, the 2800+ has 256k of cache, but it makes little differance in the majority of apps.
You can probably bring the default voltage down quite a bit on these, my newcastle 3400+ can come down to 1.425V at 2.4ghz so the smaller 90nm process, combined with only running at 1.6ghz should allow much lower voltages than 1.4V

sneaker · Post by **sneaker** » Tue Mar 08, 2005 9:34 pm

The 2600 and 2800+ are almost confirmed as not having CnQ. The 3000+ is still an unknown but the Inquirer article that originally revealed the 2600/2800+'s lack of CnQ suggests the 3000+ does have it. The 3100+ has always had CnQ, but the availability of 90nm parts isn't clear.

The situation is made more irritating by the fact that if you're to spend the money on the higher-clocked Semprons, you'd probably rather have an Athlon 64 2800+. Yet I believe the S754 A64s are still all 130nm, so while it's performance is better and 64-bit support is there, it won't have the Winchester-or-better power characteristics of the new Semprons. If the A64 2800+ were 90nm, the decision would be made for you.

VERiON · Post by **VERiON** » Tue Mar 08, 2005 11:33 pm

sneaker wrote:The situation is made more irritating by the fact that if you're to spend the money on the higher-clocked Semprons, you'd probably rather have an Athlon 64 2800+.

That is exactly what I was going to say.

It is also an alternative to aging xp-m solution (whera I live it is CHEAPER then xp-m).

But does the Athlon 64 2800+ s.754 ClawHammer (0.13) support c'n'q and allows multiplier and fsb change on the fly?

I've read i post that it does'nt - but it was only one opinion that I found - and maybe this was mobo issue, because not all mobo support c'n'q?

Anyone to confirm/deny this?

GrahamGarside · Post by **GrahamGarside** » Wed Mar 09, 2005 6:23 am

The A64 2800+ is a newcstle core I believe, at 1.8ghz

Wraith · Post by **Wraith** » Wed Mar 09, 2005 7:53 am

AFAIK, the 130nm and 90nm Sempron 3100s both have a default 1.4v, both are rated at 62W, and both run at 1.8 GHz, but only the 130nm is known to support CnQ. Is the power consumption difference between these two going to be as big as with Newcastle vs. Winchester?

Bitter Jitter · Post by **Bitter Jitter** » Wed Mar 09, 2005 9:42 am

VERiON wrote: But does the Athlon 64 2800+ s.754 ClawHammer (0.13) support c'n'q and allows multiplier and fsb change on the fly?

I've read i post that it doesn’t - but it was only one opinion that I found - and maybe this was mobo issue, because not all mobo support c'n'q?

Anyone to confirm/deny this?

I have an Athlon 64 2800+ Socket 754 Clawhammer and it does support cool n quiet allowing multiplier, voltage and FSB changes on the fly. If you use AMD's cool n quiet software its low power state is 800Mhz @ 1.35v. Newcastle is 1000Mhz @ 1.1v. If you use Crystal CPUID you can make the setting yourself my minimum state is now 1000Mhz @ 1v, making it pretty cool.

The big disadvantage with the Clawhammer is that at stock speed i can't get the voltage lower than 1.375v without causing instability so it runs around 40 - 50w at full load.

GrahamGarside wrote: The A64 2800+ is a newcstle core I believe, at 1.8ghz

AMD market it as a "Newcastle" and i'm sure most of them now are real Newcastles, but there might still be some clawhammers knocking about still. It thought i was buying a Newcastle it was only till i noticed that cool n quiet was running at 800Mhz @ 1.35 i realise that i had a Clawhammer!

As for the Semprons

Blue = Cool n quiet
Red = No Cool n quiet

3100+ @ 1800Mhz, L2 Cache = 256Kb
3000+ @ 1800Mhz, L2 Cache = 128kb
2800+ @ 1600Mhz, L2 Cache = 256Kb
2600+ @ 1600Mhz, L2 Cache = 128Kb

GrahamGarside · Post by **GrahamGarside** » Wed Mar 09, 2005 4:05 pm

My newcastle A64 can run at 1.6ghz with only 1.1V and doesnt need the fan on with the CNSP7700-AlCu so I figure a 90nm sempron must be able to achieve similar

VERiON · Post by **VERiON** » Thu Mar 10, 2005 1:04 am

Bitter Jitter wrote:AMD market it [A64 2800+] as a "Newcastle" and i'm sure most of them now are real Newcastles, but there might still be some clawhammers knocking about still.

Exactly. That is the CHEAP option i'm talking about, because clawhammer that are in the shops are really cheap.

Hey... I've just checked that a64 2800+ is has the same price tag as Sempron 3100+... which is:
- faster http://www.tomshardware.com/cpu/2005020 ... on-11.html
- and cooler running .13u SOI paris core, c'n'q enabled

___
hands down... i'm gonna get sempreon 3100+ for my budget pc (htpc).