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OC'ing a A64 3700+ San Diego

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November 8, 2005 11:20:09 PM

Is it possible, im kinda new to overclocking and this fourm. I know that with P4 based CPU's (and maybe every cpu that the core FSB speed is 200 mhz). So to get my celerons 2.0ghz speed you take the core of this celeron (which is 100mhz) and multiply by the multipler of 20 and get 2.0ghz. So if I could could OC my FSB to 200 mhz I would get a 4.0ghz processor that would burn up blacker then black.

My friend has a P4 3.0C which has the max of a core CPU FSB of 200mhz, his multipler is at 15 that gives him 3.0GHZ.

Now If I got some PC4000 ram (500 mhz, 250*20) and had his cpu I would need to raise his FSB to 250*15 which would give him a cpu speed of 3.75 ghz and his ram and cpu would be 1:1.

Now with this San Diego 3700+ i want to get, how would I oc that. Whats its max locked mulitplier??? How high can I OC the FSB before the chip becomes unstable.... im hopeing atleast to 200mhz... if thats not what it is already. If the San Diego 3700+ does have a core of 200 mhz FSB then that means I wouldnt have to touch it to be 1:1 with the PC3200 ram the ASUS A8N SLI Premium is compatable with.

Even if I dont have to OC that processor to be 1:1 with the PC3200 ram, could I OC it to work with PC4000 ram??

Or lets just forget the ram for this next question, could I alter the FSB to get some more clockspeed out of tat San diego 3700+??? If I can how high can you safely go 200mhz over, 400mhz over??



Im really new and newb to all this, so thanks to anyone with the understanding and patience.

More about : ing a64 3700 san diego

November 10, 2005 4:56:11 PM

The 3700 is a 2.2ghz cpu with a 200mhz 'fsb' (technically not the fsb because of hypertransport, but accurate enough for our use here) and 11 max multiplier.

You could OC it to work with PC4000 RAM at 1:1. 'How high you can go' depends on luck (did you get the very overclockable CPU or the one that is less OC'able?) as much as the hardware you get. Your A8N can probably OC enough to get you to 250 (or darn close). Usually on the stock HSF they can go to about 2.6ghz(a little shy of 250fsb), but with good cooling and care you may hit 2.8 or so.

You can also lower the CPU multiplier and if the mobo and ram can take it, raise the 'fsb' further if the CPU's max speed isn't high enough to run your RAM 1:1. You can also run the RAM on a divider in the opposite case (i.e., your CPU can go to 260fsb but your RAM can't) without loosing much performance (AMD's aren't nearly as bandwidth-dependent as Intel - running RAM at 166 with FSB at 200 looses about 1% performance overall - much less than the loss of running the CPU at fsb166...).

There are a number of OC'ing guides, some have been linked to in these forums, but I'm too lazy to go find them to link them... :lol:  (try a search if you're interested), so I'm going to suggest you read the Beginners guide to the Athlon XP at the top of this section (the one for the A64 is more a plug for a software tool). That gives you the basic 'how to' for overclocking. The Athlon 64 has one more 'variable', and that's the hypertransport multiplier. You want to adjust that multiplier so the HT multiplier times FSB is no more than about 1000. (i.e., it should be at 5x for 200fsb, but to go over 200, drop it to 4 until you hit about 250, then drop it to 3). You won't loose any performance until the HT speed goes below 600, so there's nothing to worry about there.

Anyways, the rest of overclocking is just taking it slow and steady, testing for stability at every step.

Mike.
November 11, 2005 12:55:29 AM

I'll make this simple. I have a 3700+ San Diego. I am using the stock heatsink/fan and I have it at 240x11 to give me 2.65Ghz. The idle temp is 29C and about 37C underload. This is such a good chip, I know it can reach around 2.8Ghz and still be stable depending on your Ram.
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November 14, 2005 1:56:35 AM

the FSB stock is 200
multi is 11

you should be able to take it up to around 250 pretty easily....thats 2750

if you want to get great timings(2-2-2-5, what i have) at those speeds i can reccomend some RAM for you...$115. it wont go much higher then 260 but thats about where your cpu is going to top out and 260FSB with 2-2-2-5 timings is going to be as fast as something thats 280FSB with 3-4-4-10 timings.

Also stock cooling for AMDs are great, but if you want something a touch better get the Thermalright SI-120. with this it pushes a lot of air and has a fan controller so you can turn it down if you want to. Sometimes 100cfm will keep your cpu the same temp as 45cfm....play with it to lower your sound levels and still get a great OC.
November 15, 2005 1:06:36 AM

2.5 GHz is easy. My 3500+ Venice is the same as your SD except with half as much cache. I'm running at 250x10 for 2.5GHz using a 5/6 (DDR333) divider to keep my ram running at 208MHz so it can operate at its best timings (2-2-2-6); idle 26C, load 37C using Thermalright XP90 heatsink and quiet fan (Vantec Stealth). Ram is 2x512 OCZ Plat 2 3200. (Stock timings for this ram is 2-2-2-5, but my DFI board prefers 2-2-2-6.) If you have this ram and a DFI board, respond and I'll give you ALL of the multitude settings.
November 15, 2005 1:10:44 AM

I meant to also say, 1:1 isn't important with A64s. Use the divider to get the O/C you want and also optimize your RAM speed for its best latency settings.
November 15, 2005 4:10:23 AM

YOu have the DFI board? why not get the VX RAM? its cheaper then the Rev2 and it will stay 2-2-2-5(or 6 if you want) all the way to 250-260fsb
November 15, 2005 12:25:43 PM

Not to be noob but what the hells a divider, what does it do and how does it work??? Do I have to buy it??
November 15, 2005 12:31:50 PM

it is your FSB/Memory ratio and control for it resides in your BIOS...
November 15, 2005 12:37:00 PM

lol....its on your board already...its an option

bascially there are set ratios you have as options......what it does is runs your ram at that ratio of the FSB.

let say you have a great OCable cpu but cheapass ram.

You can set your FSB to 250...but your ram can't do more then 200Mhz....so what do you do? Well you could use your divider.....you could use a 5:4 one (if your board has it, its a little different per board but there are some common ones) So bascially your cpu will be using the fsb at 250Mhz, and your ram will be using it at .8(the ratio 4:5 expressed as a decimal)*250fsb=200Mhz.

Back in the olden days....like 3-4years ago if you used a divider even though your cpu was faster your system would slow down unless you got a MONSTER OC for the cpu.

nowdays with the A64's you dont have to run the ram 1:1 (as a decimal that would be 1...and 1*250fsb=250fsb) you could run it at 5:6(decimal is .8333 so same example... .8333*250=208fsb for the ram), 4:5, 3:4(.758250=188fsb), and so on.

so if you had shitty ram you could use a divider and get a good performance boost without the added cost of good ram. But since good ram prices are way cheap now....you could go eiher way. i would go with good ram personally


and OCZ rev2 is just about as good as you are going to get....i like the VX because if you give it a little more power it will do 250fsb at 2-2-2-6 timings....which is like the same setup performance wise as something 280fsb with 3-4-4-10 timings.
November 15, 2005 1:19:45 PM

Well I want to take my FSB of the CPU to 250 (*11=2.75ghz) and leave the ram at PC4000 (250*2) at 2-2-2-5 which would be 1:1 so I shouldnt have to even mess with the ram at all right???
November 15, 2005 1:23:41 PM

you wont have to mess with the ram divder at all for that.....if your ram will do PC4000 speeds.
November 15, 2005 11:54:32 PM

Why didn't I get the VX ram? :? I didn't know better at the time. I wanted safe standard memory voltages. I now realize that my fears were unfounded.
By the way, pickxx, you do good posts. Your divider explanation is concise and easily understandable.
--Allan
November 16, 2005 12:09:13 AM

Its not a bad choice to go with Rev2.....that would honestly be my 2nd choice....but i just like keepign the tight timings if i can because it does some added performance without having to push your cpu to extremes....

and thank you, i try to be honest and clear.
if i dont know i wont lie or say something stupid, i will find out or say i dont know.
December 12, 2005 10:39:38 PM

Hay guys,

Yeah the stock AMD cooling solutions are not bad at all. I have my San Diego 3700 + running at 2.8 GHZ, 11x Multi with a 256 FSB...basically running at FX-57 speed with the stock cooling..but then again I have like 6 case fans in an aluminum case...there are ways to optimize a case with air cooling. But I am running my 2 gigs of ram on a divider till I can get some decent PC4000 stuff, then I can go with the 1:1 deal and get a good boost from some fast ram. Anywho yeah, the San Diego core is pretty decent for overclocking, but just remember, you need to watch temps! Mine idles at around 35-37c degrees and gets to about 46c or 47c under load...its just a great core..

Wishing I was a King in never neverland................. :lol: 
December 13, 2005 4:44:26 AM

As discussed above, unless you can improve your latency settings, there is no point in getting new RAM. The divider thing offers performance in A64s essentially the same as 1:1. Purists will say what we think of as 1:1 on an A64 isn't really; they are all on dividers. My O/c temps are 10 degrees cooler than yours; maybe I should push higher, just for the fun of it. Is your rig noisy with the stock cooler and all the fans?
December 13, 2005 6:58:45 PM

Reader 850,

I have some pretty crappy Crucial value ram..it is running at cas latency of 3.0..at like 402 mhz..It won't let me go to 2.5 or lower..I figured some good DDR500 with lower latencies would benifit me much seeing as how I could run the memory and cpu at 1:1, putting me at aound 460 to 480 MHZ memory clock with lower latencies...whats your opinion on that? I definitly think you could maybe push yours more. Venice cores are supposed to be the best for Overclocking...I just have the stock AMD heatsink and fan setup on my CPU..the case is a little loud but not much..I do not mind it at all....the loudest fans I have are my 2 high-speed 80mm Delta fans that are my intake fans at the front of the case. I have them hooked into a Vantec fan controller so I can keep them at a reasonable RPM and still pull in some cool air throughout the case...then I have dual 80mm's exhausting out the back as well as an 80mm blow hole fan on top.
December 14, 2005 1:36:45 AM

Better RAM will give you measurably better performance, but I'm not sure it will be very noticable. If you upgrade your RAM, you could go for the best DDR400 for lowest (2-2-5-2) latencies, or you could go for quality DDR500 or so with good but not great latencies and higher speed. There are two opinions on RAM. Some want the higher speeds and bandwidth even though they sacrifice latency, and others like me prefer the best possible latency, which I think gives the best result for A64s in most applications. Since using dividers isn't a negative with A64s, high speed memory isn't needed for overclocking. But the choice is a matter of opinion, so go whichever way you prefer.

I haven't stressed my Venice at all yet, because at 2.5GHz it already performs better than I need. But I'm sure I will push it higher one of these days, maybe over the Christmas holiday. Have a Merry Christmas!
December 16, 2005 1:58:44 AM

Hello guys,

Im still quite noobish to A64 ocing...(only did some moderate ocing
on XP and Bartons)

I read all over places that i should be able to OC the 3700+ to about 2600-2700 with no big issues and stock cooling ? I cant get it further than
~2450 .

Ram is set to use max 200 (but that setting seems to be misleading cause it will not limit the ram to 200 when i raise the Cpu overclock feature.
(trying to run asynch speeds i am ..and no figure how to achieve that
goal...) Cant i just raise FSB and keep ram at a lower speed ?

I want to get that baby to 2600-2700 ...whats the exact bios settings for that then ? I have fooled around a lot but since i have no twin bios its a
pain in the ass when i have to reset the bios all the time and reenter all the
ram timings that i have already tweaked to get 1T mode stable + reconfig
all other options to what they were before etc.

Ive been thru tons of threads and forums but just the simple problem is
that my bios does use naming conventions for some of its options that
seem to be misleading, especially the divider and HTT settings which are
so widely spoken about are a bit confusing for me since the options in the
bios arent named like that, also the ram speed settings are confusing...
like i wrote at the top ... i set it to 200 and it will still raise if i raise
fsb...i dont get it.

If i raise the FSB to over 226 mhz the system will hang, but thats
just about 900+ mhz HTT on a 4x divider right ? So i guess my corsair
3200 ram is not good enough then....but then i should do what ?
Lower the Ram max speed setting in the bios to 166 ?? (Weird that theres
no incrementals there...100,133,166,200,230,250 yeah but no single mhz
settings) Wouldnt it be dumb to lower my ram to 166(333) or not...argh
im getting headaches of this :D 



also:
I have various issues with CPU-Z and Clockgen

i have a divider for HTT which is set to 4x instead of default 5x,
how is this reflected in clock gen ? The HTT will not show its
end value it will only show the clock speed (200 in that case)
Would sound more logical if it would display 800 on a 4x 200 and
1000 on a 5x200 setup ?


Clockgen will not read out the correct voltage.
Currently my CPU is set to 1.55 volts (3700+ a64 SD) in
BIOS 824 version.
The software will show 1.40 volt

CPU-Z has the following oddities. (btw cpu-z reads out the correct voltage)

Wont show BUS SPEED ? (greyed out) ..normal on A64 ?

in memory tab: channels shows dual (thats correct)
Performance Mode and Bank Interleave are greyed out with no info
(both are active though since rig runs in dual channel mode)...is that
by design ?

used this version of clockgen and 1.31 of cpu-z
http://www.cpuid.com/cg.php?cgid=NVNF3


Tons of questions hope i get some feedback....

spec: DFI Lanparty UT NF3 rev 1.3 , A64 San Diego 3700+,Corsair 2x1024
mb twinx CL2
December 16, 2005 4:16:46 PM

I'll try to explain the RAM thing - though I don't have your mobo so...

Ram & FSB normally go up and down hand-in-hand. FSB=200, for synchronous operation, RAM=200. Now you up the fsb. That also ups the actual RAM clock, but the BIOS setting probably still reads 200. That's because the bios is confusing (probably someone in the 'simplicity department' thought displaying the ratio was confusing). The ram setting really sets the divider, but they display it based on the stock 200mhz fsb clock. So, ram=200 is 1:1. Ram=166 is 5:6. And so on. So, set your ram to 166, turn up your FSB and the ram moves up proportionally. (when FSB goes up 6, ram goes up 5 - or, at 240fsb, your ram is really running 200).

Hope that helps some.

Mike.
December 17, 2005 3:45:52 AM

Good explanation, Fishmahn. Saberhawk, I have a DFI NF4 Ultra D – official bios 3/10, so my bios settings might be different from yours. But just in case this might help, here is what I’m running.
Venice 3500+ @ 2.5GHz (1.36v, 10x multi, 250 HTT, 4x HT, Divider 5:6 (DDR333) for RAM speed of 208MHz) OCZ PC3200 Plat Rev2 (2X512) : 2-2-6-2 (1T) @2.8V (Bios settings: 2.0-2-6-2-8-12-2-2-1-2-2560-auto-enable-auto-0-7-2-7.0-auto-32-disable-16x-7x-disable)
ThermalRight XP 90 w Vantec Stealth: idle 25C, load 37C

In my opinion, DFI boards are far more complex and require much more work than most boards, but they also offer the greatest flexibility and potential for your CPU and RAM. You have to work at it to determine what is best for your particular board, CPU and RAM. It took me many hours of research in DFI-street.com and experimenting with my bios settings to get my computer to run well. You start out with relaxed settings for the CPU and HTT, and test your RAM to discover its maximum stable speed. Make sure it is COMPLETELY stable before you assume it is, then back it down a bit to be sure, until you get everything else tuned well. Next, if you want to, you can relax your RAM and test your motherboard for its maximum speed, and then relax those components to test the CPU for its max speed. I skipped the second and third steps, as I’m sure DFI boards will hit FSB/HTT speeds much higher than I’ll ever use, and I’m not interested in absolute maximum performance. I’m more interested in a conservative overclock that keeps the temperatures low. However, if you go to the trouble of testing each of the three components to their max, then you know the limits for your overclocking effort.

I recently studied divider strategy and easily increased my O/C with the divider setup you see above (10x multi, 255 HTT, 4x HT, divider at 5:6 (166 or DDR 333)), which when multiplied by the 255 HTT gives an actual RAM speed of 208, which allows the RAM to run at its best/lowest cas settings. My temps are still very low thanks to my ThermalRight XP 90 heat sink, so I’ll shoot for 2.7 GHz one of these days. My guess is you could do 2.5 or better easy with stock cooling. Study the “sticky” guides and many useful links for your mobo at DFI-Street.com
December 18, 2005 2:45:08 AM

cool tips

so if i set my HT to 4x and the "overclock cpu" to whatever and i set my
"maximum ram speed" to 166 , it will start overclocking my fsb at 200 + X
and my Ram at 166 + X , so i could go to lets say 11x 250 on FSB which would equal (250 divided by 6)*5 = 208 for ram speed at a 1000 HTT speed.
That would be a whopping 2750 mhz at a 208 ram speed and 250 FSB
True ? Since i know that my ram will go up to 222 at least i could go
up to 265 on "overclock cpu" but that would end up non booting cause
HTT value of 1065 ...(HT 4 x 265 fsb? ) ..would end up crunching or not ?

Btw im running this baby at 1.52 volts already and stock cooling is still sufficient.I see you dont even add vcore on your OC yet...i doubt your
temps though i think your diode is measuring way to low unless your
room is at quite low ambient temps...even watercooling would barely
lower a cpu below 30 C.


UPDATE:

Posting this at 2713 mhz :D  at 246.7 HTT,4x HT,11x multi, vcore 1.50v, AGP 68 mhz, vdim 2.70v , mem freq at 193.8 cas 2.5(stock cooler)
Not an too bad OC i would say...500 mhz above spec with a stock cooler.



Will buy better cooler soon and will cont. finetuning...at 250 i couldnt
post sometimes or load windows, prolly needs some adjustments at ram


Update:

Well it seems im down to 235 and still not stable in gaming. BF2 ran
quite snappy for a while but then machine hard locked. Too bad really,
looks like a bummer CPU ... i relaxed some stuff upped some volts
here and there but it really didnt help so far... Damn 3dmark only
scored a lousy 80 points more than at stock speeds, oh well it hates
my X800 XT PE anyways. But in BF2 it seems the 2.5 ghz is a magical
border to really get me good FPS online.

Update:

I gave up at 232...going any lower now is just no good tradeoff
I tried 2T mode instead 1T but i still was getting freezes in FEAR
at the loading of a level even though it completed the ingame benchmark.
I went back to 11x220 mhz which is stable.
Dont really know whats the culprit here ... i added volts on all sections
AGP , chipset, Ram, CPU ..i relaxed timings some more than i already
did, and i even went to 2T mode ..no luck. The rams cant be the problem
since they are running at 220 stable. Must be CPU problem. Probably
bad cooling ...anyone got some other ideas ?

Update:

After some more thinking i decided to try 3xHT 250 FSB 166 memory, 2.9
volt memory and what can i say ? I just played 30 minutes of fear without
a single crash at 27xx mhz. Whoppee.
December 19, 2005 3:25:55 AM

I hope you are still stable. If not, your should carefully test the limits of your board's FSB (that isn't the correct terminology, but I still think of it that way), your RAM, and your CPU individually, as described in the DFI-street site. Also, if you are using my bios settings for those many other bios options no one ever heard of before, read the sticky about them and relax them some. I worked up to those; some are a bit aggressive. "Tuning" my DFI board was a mixture of fun and frustration, with a lot of education and experimentation thrown in. I love it now, but not always then.
December 19, 2005 1:31:16 PM

Well i already have timings figured out for my corsairs which i need
to have to run 1T mode stable..they seem so far to be working good
for the 3xHT setting at 2700 mhz. I still have some room on the ram
side (i also changed the slots and i am using yellow now)

I just wonder how much it "cost" me to use 3xHT instead of 4xHT (which is
not stable) performancewise.
December 19, 2005 1:39:40 PM

Quote:
I just wonder how much it "cost" me to use 3xHT instead of 4xHT (which is not stable) performancewise.

As long as the HT speed (fsb X ht multiplier) is over 600 you should lose nothing in performance. There are old benchmarks around where people were playing with that setting and performance was unchanged until the HT speed got below 600.

Mike.
December 23, 2005 12:45:36 PM

My system is currently running at 230x11, at 1.45 volts. All is working as it should. Memory woltages are at 2.8 tho´...
!