Sempron 64 2800+ overclock

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hurtstotalktoyou

Platinum Member
Mar 24, 2005
2,055
9
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Okay, my Epox board's BIOS raises the voltage in +0.05v increments. In fact, the settings don't actually read "1.40v," "1.45v," 1.50v," etc., but rather "+0.00v," "+0.05v," "+0.10v," etc. I never actually checked to see whether or not "+0.00v" amounted to 1.40v, as it should. I seem to remember seeing 1.47v during the boot cycle, but that was a while ago. Anyway, kicking it down from +0.10 to +0.05 did drop the voltage somewhat.

+0.10v gives a true voltage of 1.60-1.63v, depending on CPU load.
+0.05v gives a true voltage of 1.53-1.57v, depending on CPU load.

I was able to knock it down to +0.05v and still boot Windows, but attempting to go all the way down to +0.00v was unsuccessful. So, my Sempron 64 2800+ is now running at 1.53-1.57v, 2.4 GHz, with 200 MHz RAM and 900 MHz HT. Thanks for the help, everyone!

Of course, I still need to run Prime95 to test stability. An short test (not adequate for testing stability, but still enough to max out the temp.) seems to indicate the maximum temperature under Prime95-caliber load is 61^C, which, although still not ideal, is a heck of a lot better than the 67^C I was dealing with, before the voltage drop. Also, the new test was run in a cooler room than the old, suggesting an even more dramatic drop in temperature than a simple 6^C.

Thanks again, everyone!
 

hurtstotalktoyou

Platinum Member
Mar 24, 2005
2,055
9
81
Bad news, guys. I ran Prime95 on my new voltage and it fails. I pumped it back up to ~1.62v, so we'll see what kind of results I get on Prime95, now.

But I have a question: can flashing my BIOS cause a stable overclock to go bad? Because in between lowering the voltage and running Prime95, I also updated my motherboard BIOS.

(I updated my BIOS in an attempt to fix the voltage controls.)
 

dogmir

Senior member
Dec 14, 2000
361
0
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i am getting 2.4 ghz stable on stock voltage on my 2800+ and my mobo wont go above 300mhz fsb so thats where it is staying right now...i got it pretty stable at 2.5ghz with clockgen....but when i say pretty stable i only ran prime95 for like 30 min....but at 2.4ghz i can run prime95 24/7 and it is like a rock.....woot
 

Avalon

Diamond Member
Jul 16, 2001
7,571
178
106
Originally posted by: dogmir
i am getting 2.4 ghz stable on stock voltage on my 2800+ and my mobo wont go above 300mhz fsb so thats where it is staying right now...i got it pretty stable at 2.5ghz with clockgen....but when i say pretty stable i only ran prime95 for like 30 min....but at 2.4ghz i can run prime95 24/7 and it is like a rock.....woot

I was in the same boat with my Epox 8KDA3J (which, btw, allowed me to run two double-sided DIMMs, they were 2x512MB Geil Golden Dragon PC3200 sticks, stock BIOS back when that board was relatively new). Could only get 300HTT, which was still pretty damn good mind you. But, I picked up a DFI and was able to run my Sempy 2800+ @ 345x8 @ 1.6v Prime stable, but heat was pretty bad. I was loading around 57C. I ran 2.6 @ 1.5v for normal operations and didn't go above 50C on a Zalman CNPS 7000-AlCu. A better cooler would have done wonders for me, though...bet I could have squeezed more out of that chip if I still had it.
 

SNiPeRX

Senior member
Apr 24, 2000
755
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2800+ and K8NS Gigabyte board. The cpu is at 2.4 @ 1.65v. Temps right now are 33C. WHich is nice. This is on the stock hs/fan as well.
 

hurtstotalktoyou

Platinum Member
Mar 24, 2005
2,055
9
81
Ah, well I ran Prime95 for 8.5 hours, and it passed with flying colors. So I guess it was the voltage drop that caused the problems, not the BIOS update.

That's interesting about the DFI board. You're saying I can get a better overclock from a different board, even if it has the same features?
 

DrMrLordX

Lifer
Apr 27, 2000
22,908
12,982
136
Interseting to see people still playing with Sempr0ns.

Word of advice, try to keep vcore below 1.6, ideally 1.55v. They get awfully toasty at those voltages, and volts kill over time unless you've got excellent cooling.

My Sempr0n 2800+ does 2.3 ghz stable at stock, but requires around 1.52v to get up to 2.4 ghz which just isn't worth it to me.
 

Kristofclg

Junior Member
Sep 27, 2005
2
0
0
Hi,

i have a Sempron 64 2800+ on an Abit NV8, and it is running at 2.4Ghz @ 1.48v.

nforce4 4x chipset is a really good overclocking option, and i'll try to get to 2800Mhz.

greetings from Chile.
 

ItsAlive

Golden Member
Oct 7, 2005
1,147
9
81
Hello All,
I'm currently runnin a mild overclock on an AthlonXP 2500 barton but im thinkin of upgrading to the Sempron 64 2800+ with a Gigabyte GA-K8VM800M mobo. I am pretty knew to the whole overclocking scene but i cant overlook the performance people are getting out of these chips. And the price at which they go for is unreal. I mean 2.4Ghz out of a 75 dollar chip........WOW! As far as the overclocking goes i have done alot of research to aquire the knowledge it takes to perform such a feat and have not seemed to grasp the entire concept of it all. Such things include Multiplyers, HTT settings, Ram timings, and any other useful info i may be overlooking. If someone, anyone could post a full spec analysis for the overclock on the sempron 64 2800+ chip it would be grately appreciated and they would have my undying gratitude.

Thank You All for your Time
 

cbolt67

Member
Aug 9, 2005
79
0
0
Try this article. It's on the Semron 2600, but the method to OC is the same. I purchased a Sempron64 2800+ with a DFI LANPARTY UT nF3 250Gb after reading this and I am very happy. I have it @ 2.5GHz. using the stock HSF, and increased core voltage only .1V.

http://www.xbitlabs.com/articles/cpu/display/sempron-2600.html

By the way I upgraded from an AthlonXP 2500+ running 2.3GHz. and the sempron is definitely faster.
 

Bull Dog

Golden Member
Aug 29, 2005
1,985
1
81
Originally posted by: Powermoloch
That's a bit hot my friend. My sempron goes up to 48-50 C max @ 2.07 Mhz
Are you sure you even need cooling at that speed?
 

ItsAlive

Golden Member
Oct 7, 2005
1,147
9
81
What kind of ram are you using with that setup??? I have some cheap gigaram and i havent tried pushing it to the max yet... Anyone know how good this stuff holds up?

btw Thanks for the thread too
 

mindwreck

Golden Member
May 25, 2003
1,585
1
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Originally posted by: Powermoloch
That's a bit hot my friend. My sempron goes up to 48-50 C max @ 2.07 Mhz

What kind of cooling are you using?

Your temps are a bit hot to me. I had mine at 2.4ghz 1.55v with a xp90+zalman@7v and it got ~50-55C load.
 

cbolt67

Member
Aug 9, 2005
79
0
0
Originally posted by: ItsAlive
What kind of ram are you using with that setup??? I have some cheap gigaram and i havent tried pushing it to the max yet... Anyone know how good this stuff holds up?

btw Thanks for the thread too

I'm using OCZ ValueVX in my setup. That isn't available anymore, but OCZ does have GoldVX for a bit more. The DFI LAN party board has very setting for RAM imaginable so you should be able to run most memory. I have mine sett @133 on a front side bus set @313MHz which divides down to 208MHz RAM frequency.
 

ItsAlive

Golden Member
Oct 7, 2005
1,147
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ok this is where i get lost and the hair pulling commences......LOL. when you say you have it set @ 133 is that the ram timings? Then you have the FSB at 313mhz is that the CPU frequency or something else??? Tryin desperately not to sound too noobish right now. lol
 

cbolt67

Member
Aug 9, 2005
79
0
0
Hey ItsAlive.... been back at work and haven't looked at the forums for a few days sorry. I will try to explain better. This confused me also until I got the board and played around with it to figure out how to OC an A64. I set the FSB to 313MHz. in the BIOS This determines the clock frequency of the processor when multiplied by the preset multiplier....which is 8 on my processor. So I get 2500MHz.....Now the the 133 on the DRAM settings is a divider for the memory frequency. It's based on 200MHz. So 133 divided by 200 is .665... you multiply that times my FSB of 313 and get my effective RAM frequency of 208MHz...... This is why you need a good motherboard with plenty of options when OCing these processors....I hope this answered your question. Here's a link to a bit of info I found helpful on how to OC. The first post has most of the info. If you have any more questions I will try to help.


http://forums.pcper.com/showthread.php?t=299229
 

ItsAlive

Golden Member
Oct 7, 2005
1,147
9
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Alright i think im finally starting to understand where i was getting lost. Thank you cblot for clarifying that for me and also for the speedy responses. I should have my setup soon and i think im gonna go with the gigabyte board since it seems to have the overclocking abilities i was looking for. The multiplyer was where i was getting lost and your post cleared that up for me a great deal. When i happen to finish my build i will post specs. Thanks again for being so patient with me if i happen to run into any problems i know where to come to get straight answers and that makes me feel alot more comfortable.
 

ItsAlive

Golden Member
Oct 7, 2005
1,147
9
81
OK i have the motherboard on the way should be here either today or tomorrow and the processor bout the same time. I was wondering about runnin 2 x 512Mb ram cards and how that would affect the ram speeds?? I have heard that if you run 2 dual sided ram cards it will drop the ram speed to 166mhz anybody know if this is true and how would i fit that into the equation for adjusting my ram speed?? Any help is much appreciated.
 

ItsAlive

Golden Member
Oct 7, 2005
1,147
9
81
oh yeah i also found out that the board tops out at 455mhz but thats from an unknown source so i guess ill see once it gets here.
 

ItsAlive

Golden Member
Oct 7, 2005
1,147
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81
just got back from the PC store in town and picked up the sempron 64 3100 chip still waiting on my motherboard to arrive but ill have specs listed by the end of this week, hopefully. :)
 

cbolt67

Member
Aug 9, 2005
79
0
0
Originally posted by: ItsAlive
OK i have the motherboard on the way should be here either today or tomorrow and the processor bout the same time. I was wondering about runnin 2 x 512Mb ram cards and how that would affect the ram speeds?? I have heard that if you run 2 dual sided ram cards it will drop the ram speed to 166mhz anybody know if this is true and how would i fit that into the equation for adjusting my ram speed?? Any help is much appreciated.

I remember something about being limited to 166MHz with two sticks, but I don't know exactly what the issue was. I have 2x512MB sticks in my board and it runs fine. My memory is running @ 208MHz. no problem.
 

ItsAlive

Golden Member
Oct 7, 2005
1,147
9
81
Ok i got everything set up now but i ran into some problems with this particular mobo. First off it has no PCI/AGP locks and second i got a Rev. 2 of the K8VM800M and there are no memory divider adjustments. Since i got the S3100+ the multiplyers are all unlocked but i dont really know how to get it to run a higher multi than 9x. I think i should have went with the nf3 board afterall.
 

ItsAlive

Golden Member
Oct 7, 2005
1,147
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81
Im tryin real hard wether to return the board and go for a lil better one or just be stuck with what i got until i can grab a new board. :(
 

ItsAlive

Golden Member
Oct 7, 2005
1,147
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I went ahead and got a different board i Purchased the Gigabyte K8NS Pro. It seems to have all the features after i updated bios and works with my 1Gb of ram so i guess its on to the overclocking and should have it runnin much faster than stock shortly. :)