Socket A Semprons work as MP

M

MD_Willington

2[H]4U
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Jul 15, 2004
Messages
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FYI...

Well what makes a Sempron a Sempron...They reused the MP bridge and told the mainboard manufacturers that MP bridge closed = Sempron on a single socket A mainboard.

You can read the Sempron Data sheet about the usage of the MP bridge at AMD's website.

They aren't certified for SMP ....now you can put a couple Semprons into your aging Dual Socket A rig and let the fun begin...not much of an upgrade I'll admit but a lot cheaper tha buying a couple of MP2800+'s...

It does work...

Courtesy Rebels Haven Computer Forum:

http://www.rhcf.com/sisubb/ultimatebb.php/topic/7/128.html#000004

Have fun...

MD
 
Too bad the mobos are so expensive. I'd love to build one just to have a dually.
 
I saw a few K7Ds on Ebay for $120 and under.
Thats what I used on my last duallie system. Great board.
 
Hmm... what the hell is a sempron anyways? Would this be a better choice over the mobile bartons at this point in time? I've got a K7D right here as well.
 
Looks like the semperon could be the next low budget dual system, love to give this a shot if I had the money.
 
I'm not sure how far Semprons overclock, but for me at least Dual Mobile Bartons are the way to go if getting a 760MPX system roaring along is a priority. (Also if you're up to blowing bridges on the MSI K7D, or you can settle with other boards that don't need such mods) I think the Sempron doesn't need any bridges blown since they're apparently "set" how the MP bridges are usually set, and thus are not differentiable from MP processors on the motherboards.


IIRC, Sempron's xxxx+ ratings are supposedly weighed against Celeron processors, while normal AthlonXP processors are weighed against Pentium 4 processors. If you need to save money though, I see nothing wrong with saving $50-80 on a pair of Semprons over a pair of Mobile Bartons. It should still get you ahead most single CPU systems for threaded things and be very responsive for other things too :)


If anyone here does put a Sempron system together, please post some results in the benchmark thread I'm trying to collect. I'm pretty sure the only AthlonXP-series I have in there are all Barton cores since all of the AthlonXP's listed score predictably within other Barton-core scores.
 
Isn't the FSB on a Sempron-based system higher than most dual K7 motherboards can handle? I don't know how many BIOS' would allow that to be changed if that is the case...
 
Model 8 versions have the Athlon XP "Thoroughbred" core, while Model 10 versions have the Athlon XP "Barton" core. Or is it Model 8's are T-Bred A while Model 10's are T-Bred B? Anyway, all Socket A Semprons have a 166MHz FSB (DDR333) and 256KB of L2 cache, except the 3000+ which is a Model 10 with 512KB of L2 cache.


2200+ = 1.500GHz (Model 8 or 10)
2300+ = 1.583GHz
2400+ = 1.667GHz
2500+ = 1.750GHz
2600+ = 1.833GHz
2800+ = 2.000GHz (Model 8 or 10)
3000+ = 2.000GHz (L2=512KB) (Model 10 only)


There is also the 3100+ which is a Socket 754 CPU with 64-bit extensions disabled. It is 1.8GHz. Future Semprons will be available in Socket 939, according to AMD's CPU roadmap.
 
Order said:
Isn't the FSB on a Sempron-based system higher than most dual K7 motherboards can handle? I don't know how many BIOS' would allow that to be changed if that is the case...
Click to expand...


The FSB isn't really a problem -- it is easily offset by upping the multipliers through the Multipler Pin-Mod (I think it applies to most/all Socket A AthlonXP & probably also Sempron processors). For example, I'm running 136*18 although the Mobile 2400+ processores are factory set to run 133*13.5 or something. (Mobile processors also default to a multiplier of 6 when they're confused in non-mobile K7 systems, so without pin-modding I'd be at 133*6=800)


You just have to up the multipliers to off-set the lowering of the FSB in order to get the same clock speed.
 
Socket A semprons are all hard locked, pin mod does not work...but you can mod them to be mobiles..

The FSB is 166MHz (333) on the socket semprons. most dual rig FSB officially only support 133 (266) FSB, some overclock.

Athlon MP's are damn expensive, Semprons are dirt cheap. So if you want a mild mannered dual rig you can pick up a couple of cheap semprons and put them in your dual board.

We're not talking stellar performance but they will get the job done.

Now if you set the FSB to 133 as supported on the main board...
OPN = SDA3000DUT3D | 12.0 x 133 MHZ ~ 1600MHz
OPN = SDA2800DUT3D | 12.0 x 133 MHz ~ 1600MHz
OPN = SDA2600DUT3D | 11.0 x 133 MHz ~ 1460MHz
OPN = SDA2500DUT3D | 10.5 x 133 MHz ~ 1397MHz
OPN = SDA2400DUT3D | 10.0 x 133 MHz ~ 1333MHz
OPN = SDA2300DUT3D | 9.50 x 133 MHz ~ 1263MHz
OPN = SDA2200DUT3D | 9.00 x 133 MHz ~ 1197MHz

MD
 
So then isn't it advantageous to simply pin-mod a pair of XPs and circumvent the need for a slower dual Sempron system in the first place?
 
Order said:
So then isn't it advantageous to simply pin-mod a pair of XPs and circumvent the need for a slower dual Sempron system in the first place?
Click to expand...

- If they are super-locked the pinmod may not or will not work.
- You also need to have the MP bridge closed in most cases.
- The XP's are getting pretty expensivew compared to the Semprons.

MD
 
Yeah, that makes sense to me now.
If they're completely phasing out the XPs in favor of the Semprons then the whole supply/demand thing makes the XPs pricier.
Ah well.
I didn't even know they "superlocked" some of their chips.
My last dual system used MPs....before I knew the XPs could be unlocked. It lasted me a good 2 years though so I think it was worth the extra money.
 
MD_Willington: said:
Socket A semprons are all hard locked, pin mod does not work...but you can mod them to be mobiles..
Click to expand...
What would this do exactly, unlock the multipliers?


Athlon MP's are damn expensive, Semprons are dirt cheap. So if you want a mild mannered dual rig you can pick up a couple of cheap semprons and put them in your dual board.
Click to expand...
Wouldn't it just be better to get two mobile processors and mod them, especially from a performance perspective?


Now if you set the FSB to 133 as supported on the main board...
OPN = SDA3000DUT3D | 12.0 x 133 MHZ ~ 1600MHz
OPN = SDA2800DUT3D | 12.0 x 133 MHz ~ 1600MHz
OPN = SDA2600DUT3D | 11.0 x 133 MHz ~ 1460MHz
OPN = SDA2500DUT3D | 10.5 x 133 MHz ~ 1397MHz
OPN = SDA2400DUT3D | 10.0 x 133 MHz ~ 1333MHz
OPN = SDA2300DUT3D | 9.50 x 133 MHz ~ 1263MHz
OPN = SDA2200DUT3D | 9.00 x 133 MHz ~ 1197MHz
Click to expand...
Based on the above chart, 1600MHz is the best clock speed one can hope for using the Semprons with no possible FSB and multiplier adjustment. What is the current roadmap for socket-A processors? Are these Semprons the end-of-the-line?
 
Tim_axe: said:
The FSB isn't really a problem -- it is easily offset by upping the multipliers through the Multipler Pin-Mod (I think it applies to most/all Socket A AthlonXP & probably also Sempron processors). For example, I'm running 136*18 although the Mobile 2400+ processores are factory set to run 133*13.5 or something. (Mobile processors also default to a multiplier of 6 when they're confused in non-mobile K7 systems, so without pin-modding I'd be at 133*6=800)
Click to expand...
How did you get the mobile processors running at such a high clock speed with no stability issues? Which specific processors do you have, and what board are you running?
 
APOLLO said:
How did you get the mobile processors running at such a high clock speed with no stability issues? Which specific processors do you have, and what board are you running?
Click to expand...

Processors:
2x AthlonXP-M Barton 2400+ (35watt) IQYHA 0402 Stepping/Date
Currently 135*18 = 2430 @ 1.75 volts -- CPU0 Temp 48c, CPU1 Temp 60c, Case Temp ~37c
Ordered From NewEgg back when they were introduced around ~$80-$90 (Prices have gone up a bit now) I would have tried the 45watt 2600+, but they were too expensive compared to the relatively unknown/new 35watt 2400+ processors.

Motherboard:
Gigabyte GA-7DPXDW-P
This board will accept mobiles without what is known as Bridge Modding. I think the MSI (or IWill?) board requires some Bridge Modding with Mobiles before accepting them as SMP capable. PinModding multipler is still needed.

PowerSupply:
Vantec Stealth 520watt
Just get a quality PSU -- like Antec or Fortron. SiSandra estimates my processors consume ~110 watts each. :eek:


Stability:
I can't keep both processors @ 2.5GHz (140x18 IIRC) - but individually they can each hit 2.5GHz. I speculate I run into thermal issues -- the processors get unstable when above 60 (c). As appears common in Dual CPU systems, one of the two processors is always 10-15(c) hotter than the other -- I've confirmed this by feeling the HSF with my hands.
 
Tim_axe: said:
Processors:
2x AthlonXP-M Barton 2400+ (35watt) IQYHA 0402 Stepping/Date
Currently 135*18 = 2430 @ 1.75 volts -- CPU0 Temp 48c, CPU1 Temp 60c, Case Temp ~37c
Ordered From NewEgg back when they were introduced around ~$80-$90 (Prices have gone up a bit now) I would have tried the 45watt 2600+, but they were too expensive compared to the relatively unknown/new 35watt 2400+ processors.

Motherboard:
Gigabyte GA-7DPXDW-P
This board will accept mobiles without what is known as Bridge Modding. I think the MSI board requires some Bridge Modding with Mobiles before accepting them as SMP capable. PinModding multipler is still needed.
Click to expand...
Thanks for all the detailed info!

If I wanted to upgrade my current processors (underclocked 2500+ Bartons), would you recommend the 45W 2600+ mobiles over the 2400/2500 mobiles and the Semprons? My board is a Tyan S2462 UNG; I'm assuming bridge modding and pin modding would be necessary to get well over 2GHz... Thinking about that almost makes me want to pay someone to do it.
 
APOLLO said:
What is the current roadmap for socket-A processors? Are these Semprons the end-of-the-line?
Click to expand...

Semprons are considered end-of-the-line. (Barton core AthlonXP is considered the pinnacle of Socket A I think -- then along came the Mobile Bartons :D) On AMD's roadmap, the AthlonMP family has an unknown "As Market Demands" bubble or something like that. But I think AMD would rather push Opterons as the server platform instead of keeping the older AthlonMP's around. Despite being older and pushed aside, AthlonMP/760MPX is awesome -- the motherboards has 2 databuses for example, and there are also 64bit/66MHz PCI slots supported.

AthlonMP/760MPX was doomed since about about a year or two before Opteron ever made it to market, because all of the Motherboard Manufactuers "waited" to see when Opteron would infact make it to market, and they didn't work on any really nice AthlonMP boards. Which is why there are only 6x 760MPX board manufactuers on the market and a handfull of board offerings. (Asus, Tyan, MSI, Gigabyte, IWill, and Epox) ( Link of Interest: http://techreport.com/reviews/2002q4/mpx-boards/index.x?pg=1 )



I hadn't known that the processors now came "Super Locked." The only thing I can think of after some research is that they began insulating some broken bridges on the PCB so that the mods no longer repaired the severed bridges like they used to. Now the conductive paint doesn't connect the path because the original conductive material isn't exposed -- it is insulated. But I haven't seen these myself, so this is just speculation. I'm not sure how great of an idea Semprons are if you can't overclock them to stay with the curve...




Edit: I don't know much about your board -- but if you search at 2CPU Forums ( http://forums.2cpu.com/ ) you might be able to find some better information than I can provide. I haven't kept up with new stuff much after I got my system working nicely.
 
I would say Semprons are end-of-the-line for Socket A. There will be Sockets 754 and 939 incarnations of them down the road, which would basically make them Durons of the future, being budget entries compared to Athlon64s and up.
 
Socket A is through...

Mobile mod a sempron is the same as mobile mod a XP or an MP.

Links:

http://fab51.com/cpu/barton/athlon-e24.html

http://www.cpuheat.wz.cz/html/AXP_multiplier/AXP_Multiplier.htm

http://www.ocworkbench.com/2004/guides/unlockbartonwk43/unlockbartonwk43-1.htm

AthlonXPmod.gif
 
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