Looking to get some more mileage out of my 3800+

[Pring4]

Hello all, first post on these forums.

I've noticed my system is starting to show it's age, so I'm going to give another shot at OCing. Currently I have the following:

Asus A8N-SLI Deluxe
AMD X2 3800+ (Toledo)
2x512 OCZ EL Platinum Revision 2 PC3200 (Rated at 2-2-2-5)
Rosewill Radeon x800 XL
Then some HDs/Soudcard/etc.

I followed the quick and dirty OCing guide on the forums and had some success with that but ran into a few problems. When testing my max chip and max FSB, the guide says to set memory to SPD and 100 to take it out of the equation. Based on my mobo/BIOS, I couldn't really find any option to do this. The best I could do is to set the memory timing down to its lowest 200mhz. After getting through that my FSB is not set at 305.

The same can be said when testing my chip about trying to get rid of the memory variable. However, I was not able to get this too high because my mobo has it's voltage locked (as best I could find). Based on this test, my highest stable is 10x250.

It's particularly bad when testing memory when I don't know my settings well enough - nor could I even get memtest working because my floopy drive isnt working and I went through 2 coasters trying to burn the iso! I found a guide on Anandtech which overclocked the Manchester 3800+ with similar ram, and used their settings of 2.5-3-3-7-T1.

Currently, the memory is still at 200mhz, CPU voltage at 1.475, FSB at 250, multiplier at 10, and RAM voltage at 2.8. I have not run prime95 for an extended period of time yet, but everything seems to be stable.

I have a pretty good heatsink/smartfan combo, so sitting idling here at 2.5ghz Asus prove says my CPU is at 34c and mobo is at 32c. I think I can get 2.6 out of this 2.5 year-old setup - what do you think?

 

[MarcVenice]

1.475 vcore is pushing it. I wouldn't go any higher then that personaly. I can do 2.5ghz on 1.3vcore btw. Since I've got a nforce4 board, and 4x512mb the mobo will only run it at ddr333, some more vram will get it to run faster though, but the FSB on my mobo won't go past 260 as far as I'm concerned so I can't really get past 2.6ghz.

Also, put your memory at 4-4-412 2t, that should help, if you reach your max core speed, you can start tightening the timings again. Btw, couldn't you find a divider for your memory ? Thing is, if your memory is at 200mhz, and you increase your FSB, your memory speed will also increase. It probably won't do much more then ddr500, which is what it is at now. Doesn't CPU-Z tell you the memory speed?

 

[Pring4]

OK Thanks, I'll make those adjustments and see how the bench changes.

But for the memory timings, I assume you mean 4-4-4-12, correct? And from where I've read, a64's benefit from 1t as opposed to 2t. Or is this just the safest possible area for memory to find my max FSB, then tighten the timings down?
But to be honest I couldnt find a divider for my memory. It's rated at 200mhz (pc3200), but under the timings in CPU-Z I'm getting:

Frequency: 125mhz
FSBRAM: CPU/20 <-- Obviously there's something I'm not doing right.

Edit:
I found this info on a post at Overclock.net.

Memory Dividers:
As you will now know the use of memory dividers becomes important when getting the maximum out of your system. This maybe because the CPU can go higher in Mhz and you need to keep the memory from going over its max limit.

Unlike other MB?s the Asus does not directly have what is seen as a memory divider where you see ratios of 5:6 or 9:10. Instead to get your memory onto an equivalent divider you need to set Max Mem to a lower DDR value, this will effectively place the memory onto a divider.

Eg:
Set Max Mem : DDR333

So I get mine is already set at a lower value - 200mhz. I'm not sure exactly how that works out mathematically though.

 

[Pring4]

I changed the memory timings as per your recommendations (although the highest I was able to chose for the CAS latency is 3), but kept the voltage the same. The highest I can get my processor to go without failing within the first 5 minutes of Prime95 is 2580mhz. Are there any other changes I can try to make to get my processor speed up according to the A64 overclocking guide?

 

[dustmann]

Make sure that you're looking at the HT (hyper transport) multiplier. I'm not sure about your stock clock speed, but I'm guessing it's around 200mhz, which would merit a 5x HT multiplier (to give you 1000mhz). So if your up to 250x5 you've got your HT bus going wayyyy to fast. Knock it down to 4x and you should be a lot more stable. A safe operating range (in my experience) is ~900-1100. Keep in mind the HT bus is 1x up and 1x down, so 1000x2 gives you the 2000mhz bus speed that is advertised.

 

[Pring4]

Sorry, I should have mentioned that earlier. But I did knock down by HT multiplier to 4x before doing a lot of these tests. I'm in the middle of testing the top speed of my memory using the guide's suggested 2.5-4-3-7-1T timings, so I'll make a post with what I find.

Thanks for the help!


EDIT:
I was able to bump up my FSB all the way to 305 and Memtest would still complete tests 5 and 6 with no errors. When I tried to bump it up to 307, it wouldn't post. Although memtest said that I was effectively running at DDR. So I guess that means max safe RAM is around 280 (DDR560)?

Although I'm still not sure what to do about optimizing the chip

 

[Ketchup]

Sounds like you are making good progress. I see you still haven't gotten any higher core speed, but you have found the max of your memory, which is good.

What cooling are you using on the cpu and what are your temps like? If you temps are good you might be able to safely push 1.5 volts on the chip. If you are using the stock heatsink and fan, you probably aren't going to get much higher than 2.6

One more question, are you running your ram in single channel or dual channel mode? Dual channel does give an ever so slight performance improvement, but is harder on the memory controller and will limit your overclock since the mem controller is on the cpu.

 

[Pring4]

Right now I've got the same coolor as you - the XP-90 with a Thermaltake 4800 rpm smartfan on it. I haven't run Prime95 for an extended period of time because I can't quite figure out the right settings to use to get it as highest as I safely can. But when I have run some stress tests for 5 minutes to see if I encountered any errors, I never saw the CPU temp go above 52/53C.

As far as pushing the voltage on the chip I think the max my BIOS allows me to do is 1.475. I'm not looking to do any Hardware mods this time around.

Edit:
Sorry, forgot to mention that it is 128-bit dual channel. Just under the no-boot FSB speed of 307, Memtest it said that it was running around 150Mhz (DDR301). While this was at a DDR voltage of 2.9, I could probably go higher by pumping up the voltage a bit more. But I'd rather be safe than get a few extra mhz.

 

[Pring4]

Originally posted by: dustmann
Make sure that you're looking at the HT (hyper transport) multiplier. I'm not sure about your stock clock speed, but I'm guessing it's around 200mhz, which would merit a 5x HT multiplier (to give you 1000mhz). So if your up to 250x5 you've got your HT bus going wayyyy to fast. Knock it down to 4x and you should be a lot more stable. A safe operating range (in my experience) is ~900-1100. Keep in mind the HT bus is 1x up and 1x down, so 1000x2 gives you the 2000mhz bus speed that is advertised.

I was able to get my FSB to about 305 with a 4x HT multiplier. However, I'm at 335 and rising with a 3x HT multiplier. Which would be more desireable?

 

[Pring4]

I've redone all the tests after looking more at the original guide post and dropping the HT multiplier to 3x from 4x. After going through it all a couple times before, I now know much more about the problems other people were running into. But here is what I Found.



FSB:
Failed to boot at 365. 365 x 0.95 = 346

CPU:
Multiplier of 259 got through 5 minutes of Prime95 - Multiplier of 260 did not make it. 2610 x 0.95 = 2480. I decided to bump it up to 2500 since it's a much more round number. I'm going to leave Prime95 running overnight after this post to see how it does.

Memory:
Kept bumping memory up as it approached FSB. Memtest failed near the end of test 6 with a FSB of 345. 345 x 0.95 = 328

 

[MarcVenice]

Memory and FSB of 345 ? I think you're confusing two things. The multiplier of 259 is the FSB speed of your cpu, the multiplier is at 10. With 345 you're referring to the memory speed, which I guess is at 345mhz, instead of the stock 400mhz. Btw, the 200mhz you see in your bios means it's running at ddr400. It's half, because ddr stands for double data rate, 400/2 = 200, see ?

You should really just look in CPU-z and see what it's telling you about your memory, then double that. So if it says it's running at 175, it's actually running at ddr350 speeds. I told you to put your memory at 4-4-4-12 2t just to be safe, and yes, later on you can tighten those timings again. CPU clock speeds trumps memory speed though, so even if you have to run at somewhat slow memory speeds, you will gain more because of the higher cpu clock speed.

 

[dustmann]

Originally posted by: Pring4

I was able to get my FSB to about 305 with a 4x HT multiplier. However, I'm at 335 and rising with a 3x HT multiplier. Which would be more desireable?

I think once you're up around 300mhz a 3x multiplier is a bit more stable. My machine is unstable at around 850, and 1150. Though it'll boot into windows at 1200, it fails prime pretty quickly.

Remember that the memory timings in your bios are simply dividers. So setting your mem divider to ddr400 will make a 1:1 ratio with your cpu speed. At 300 mhz, using the ddr400 divider will give you ddr600 (300mhz). Likewise using a divider of ddr200 will run at a 1:2 mem/cpu ratio.

So if you are using ddr500 memory (this is how my setup is) I use a cpu timing of 250mhz with a 4x HT, and a 10x CPU with a ddr400 (1:1) divider to give me ddr 500. That isn't 100% stable, so I usually knock it down to ddr333 and I get something like 208mhz (ddr416) on the mem speed with 2.5-4-3-7 timings.

Here's a reference:

266mhz/DDR533 = 4:3
250mhz/DDR500 = 5:4
233mhz/DDR466 = 7:6
216mhz/DDR433 = 13:12
200mhz/DDR400 = 1:1
180mhz/DDR360 = 9:10
166mhz/DDR333 = 5:6
150mhz/DDR300 = 3:4
133mhz/DDR266 = 2:3
120mhz/DDR240 = 3:5
100mhz/DDR200 = 1:2

 

[Pring4]

I probably am misunderstanding something about the memory.

So let's say that my FSB is running at 345mhz while my memory is at 200mhz. Loading up Memtest, I can get through tests 5 and 6 successfully at 173mhz (DDR346). But I the tests fail when I bump my FSB to 350. So let's say my safe mem speed, based on the guide, is 350x0.95 = 333 FSB for memory - am I correct? But because my memory is rated at DDR400, I will worry about bumping up the memory speed from 200mhz to 266, or 333 later, correct?

Say that's all correct for my top speeds of everything. So in the A64 script mentioned in the guide (http://math.gogar.com/athlon64.cgi), I would put in the following:
CPU: 2520
RAM: 333
HT: 1038 (3x HT multiplier X 346 FSB)
HTT/FSB: 346
Multiplier: 10x (The highest my mobo allows)

EDIT:
Ah, I'm starting to get it Dustmann.
So for my CPU speed I have my FSB around 251. I should put my memory divider at 266 to give me a memory speed of about 180mhz (DDR360). That's still well under the rated DDR400, though. But the next option up my motherboard allows me to chose is 333, which would be way too high for my memory.

 

[dustmann]

Originally posted by: Pring4
I probably am misunderstanding something about the memory.

I think you're right

What you are doing is attempting to find your absolute max cpu speed. Memory and cpu speeds are completely different things. To find your max cpu speed set your memory to the lowest divider (say ddr200), and set the timings as high as they can go (really loose, say 4-8-8-16). Now, your memory is running so slow, there is no way memory is causing crashes. So you bump cpu speed up (remembering to keep the HT in mind, which you are doing) until you crash, then drop it down by 5%.

Once you find the max, STABLE cpu speed (passes prime for 24hrs) that's when you can start speeding up your memory or tightening timings.

EDIT - forgot to mention, keep the CPU multiplier really low also (like 7 or 8) and AVOID using half steps i.e. 9.5.

 

[Pring4]

Right now my timings are at 3-7-7-16-2T - the highest they will go. My FSB is running at 260 - making my HT at 780, well below 1000. Prime95 fails a torture test within the first 60 seconds at this speed. Should I continue to bump up the FSB until my system crashes/fails to POST or should I knock it back 95% at this point right now.

 

[MarcVenice]

How much voltage you giving your core ? At 2.6ghz you might need to give it some more juice, like 1.4-1.45vcore.

 

[dustmann]

You can leave the mem at 1t as it really only applies to having 2 dimms (1t) vs 4 dimms (2t). You are probably failing prime because of the low HT speed. What is your memory divider at? You should be able to bump the cpu up way higher than 260. My 3800 manchester maxes at around 377.

I don't know asus' memory divider settings in bios. But from what I've read in this post, it looks like you've set the memory at a 200mhz divider (1:2) Which should be plenty low enough. The reason cpu-z was giving you 125mhz was because you had a cpu clock of 250 and the above 1:2 divider.

Originally posted by: Pring4
But to be honest I couldnt find a divider for my memory. It's rated at 200mhz (pc3200), but under the timings in CPU-Z I'm getting:

Frequency: 125mhz
FSBRAM: CPU/20 <-- Obviously there's something I'm not doing right.

So I get mine is already set at a lower value - 200mhz. I'm not sure exactly how that works out mathematically though.

 

[dustmann]

I forgot to mention when finding your max cpu speed, keep the multiplier down to like 7, so you can really crank it up (that's how I got 377). After you find your max cpu clock, you can tinker with the multipliers (300x9 vs 270x10).

 

[Pring4]

MarcVenice - Voltage is at 1.45, which I believe is the highest my A8N-SLI can do without a hardware mod.

dustmann - I guess it could be the voltage that's holding it back. My memory divider was at 200, which is the lowest. The next options for memory dividers are 266, 33, 400, and it continues upward. I'll set the memory back to 1T and see if anything changes in the Prime95 test.

EDIT:
Ah, I'll try lowering the multiplier too.

 

[Pring4]

Just finished up a round of tests with not much gain.

The following FSBxMultipliers would not even boot
345x7.5
345x7
335x7.5

The following would boot, but would fail in the first 5 minutes of prime95 when using the Dual Core testing method described at the end of the guide.
325x8
324x8

I did pass 6 minutes of 324x8. That's the highest speed I've attained while successfully getting through a 5 minute test of Prime95. I guess it could be the voltage that's holding me back from realy getting my FSB up higher.

 

[dustmann]

I don't think it's the voltage, maybe your chip just can't handle that high of a clock speed. I don't think you'll probably end up needing to go much higher than 300 anyways. I'm running 1.4575 vCore and it's stable up to 2600 (260x10)

 

[Pring4]

Ok, I guess that's my max CPU speed then without getting into too much detail. I left Prime95 running overnight at 2500mhz with no problems, which I admit seems a bit low for a 3800+. And since I figured out earlier my max FSB is 346 with a HT of 3x, that just leaves the memory.

When I did those tests, the highest I could get it up to was 345 where it failed at a 2:1 dividier (200 mhz). I'm beginning to understand the dividers, but not how they fit into Gogar's script (http://math.gogar.com/athlon64.cgi). In that field for RAM, should I put 345mhz or 175mhz that Memtest reports.

Again thanks for everyone's help and patience as I try to grasp all this.

 

[dustmann]

In your case, you would put 172.5 in the script. To get your ram speed in mhz, you take the cpu speed * divider ratio.

In your current scenario it's 345 * 1/2. 1/2 being the 200mhz divider. Should you bump your memory divider up to 400mhz (ddr400), your ratio is 1:1, so at that speed it would be 345 * 1/1. At a 266mhz divider you would take 345 * 2/3. And so on and so forth.

 

[Ketchup]

I would recommend using the highest CPU multiplier and the lowest ram divider to find your max cpu speed. Remember that your motherboard can only clock so high, 345 might be your max. Besides, with the way A64 systems work, the only reason to lower your multiplier and crank the fsb is to run a higher ram speed, which you do not want to do right now.

 

[myocardia]

Pring, your RAM has TCCD IC's. With 2.9v of vdimm, it will easily run @ 250 Mhz, with 3-4-4-8 1T timings, and should do 250 Mhz with lower (faster) timings. Your 3800, on the other hand, is 2.5 years old, and 2.5 years ago, 3800 X2's were only doing ~2.5 Ghz. So, you're most likely going to have to "settle" for running it at 250x10, with your RAM @ 1:1, using the 400 Mhz DDR RAM divider in your BIOS.

Of course, your cpu isn't what's holding you back, if you're a gamer. That honor belongs to your X800, which is only one generation newer than a 9800 Pro. If I were you, I'd seriously consider getting a faster video card, assuming you're a gamer.