Overclocking Athlon - urban legend?

This has been confusing me ever since I got my first Athlon - 750Mhz (Slot A).
It was the most overclocking-friendly model (considering you got the right batch, which I have - even triple checked the info).

Surprisingly, even a smallest overclocking to 800Mhz resulted in the machine looping in a reboot sequence or simply failing to start at all.
(Notice the officially AMD Certified power supply!)

My present and last AMD (no more, thank you!) is/was an Athlon XP 2600+ 400Mhz FSB. Surprisingly it is not 2.6+Ghz, but merely 1.9, which I got used to after a while (Please, I don't care how much Intel/Cyrix/Motorla has to squeeze to compare. I want exact clock frequency!).

What puzzles me still is that although it got 400Mhz FSB printed all over the package, and my K7VT6 Asrock motherboard has 400Mhz FSB setting - it doesn't work at 400Mhz FSB. Period.
Additionally, K7VT6 is a good mobo for overclocking, or so it is said. It simply doesn't work.

So, what conclusion can I draw from this? Can one really overclock the Athlon machine? I have never or used overclocked one, only heard a lot of stories.

As for my next? Back to the good, old, reliable Intel.
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  1. Quote:
    Surprisingly it is not 2.6+Ghz, but merely 1.9
    not suprising at all, as that's the speed it's supposed to run at. it's called a 2600+, not a "2.6+Ghz". "Ghz" appears nowhere in the name... I thought we'd seen the last of this kind of mistake... ah well.

    Please, I don't care how much Intel/Cyrix/Motorla has to squeeze to compare. I want exact clock frequency!
    Not wishing to offend, but that makes you stupid. The rest of us want performance.

    K7VT6 Asrock motherboard has 400Mhz FSB setting - it doesn't work at 400Mhz FSB. Period.
    Well, AFAIK the Athlon XP 2600+ was available in 133Mhz (266 DDR) FSB, or 166Mhz (333DDR) FSB. if yours is running at 1.9GHz that makes it a Barton 2600+, which has a multiplier of 11.5...

    There was never a 200Mhz (400DDR) FSB note how the '400' is actually 200Mhz, but DDR (Double Data Rate to give 400Mhz in Marketing speak). It's possible your BIOS has an option for 400Mhz, but you wouldn't have a hope in hell of that working (unless it's actually listing the DDR rating of course, but they don't, usually) Assuming you're choosing the 200Mhz option, that would try to run the chip straightaway at 2.3Ghz which may well be possible, but would require more voltage, and better cooling.

    Besides that, your memory might not be able to cope, or may need more voltage and/or slacker timings for that to happen properly, or to run the memory at a ratio other than 1:1. You may need to manually lock the AGP/PCI buses, if that motherboard supports it, which brings me to my next point:

    Additionally, K7VT6 is a good mobo for overclocking, or so it is said.
    It isn't. You should have got an Nforce2 board.

    On the whole, you sound a bit bitter over things you simply misunderstood. I've bought plenty of AMDs and are quite happy with them, because I knew what I was doing, so knew what to buy.

    I had (still have actually) a Athlon XP1700+ (Which runs at 1.46Ghz stock) which would run at 2.3Ghz (something akin to XP 3350+) with the right cooling and voltage.

    My current AMD machine is in the sig....
  2. Makes sense.

    As far as I was told the number (as in 2600, 2800 or 3000) on Athlons XP was equivalent of Intel cpu clock frequency compared to the Athlon's performance (not sure if this makes sense). But thanks for clearing this up for me.
    As I said, I would really prefer the actual CPU frequency in the name, but that is an optional wish.

    As for the K7VT6, it has got 3 jumper settings of 233/333/400Mhz. As my AthlonXP is 400Mhz I set the jumper setting accordingly. After that the machine simply wouldn't start. I had to reset CMOS and set the jumper to 333Mhz. That doesn't make much sense to me. The memory on the other hand is also 400Mhz and is set and working at this frequency.

    In regard to how good a mobo is for overclocking, here is example from one of the overclocking forums:

    Asrock is definately gonna have all the settings youll need to overclock. And what youll reach depends on your setup. 3ghz is unlikely unless you have water-cooling, phase change or some kind of extreme cooling.

    My aim ofcourse wasn't 3Ghz, but perhaps 2.0-2.3Ghz. It couldn't manage even that.
    And ofcourse, there are lots of different opinions on the matter. But this wasn't the only post in regard to overclocking using this particular mobo make/model.
  3. In order to overclock a cpu, you must overclock the FSB (or HT at latest Athlon64's). Unless you have an unlock CPU multiplier, witch i don t think is the case here:)

    The thing is that there are other components (such as DDR SDRAM) that work at the FSBx2 frequency.
    If you want to overclock your CPU, the first thing you have to do is to make sure the RAM will handle the desired clock frequency.

    Now let's say you got DDR PC2700 that works at 333Mhz. that means that you have the FSB working at 166Mhz. That means that even if your MB can handle 400 Mhz (2x200), it will not happen, for that, you need DDR PC3200 that can do 400Mhz.

    Now, if you want to overclock, and the RAM can't handle the higher frequency, you may change the 1:1 ratio between the CPU and DDR. How? you simply set you ram to work at (133)266! from bios (you might also find ratios in bios 3/4, 1:1, 1/2 etc that represent the samme thing actually) and then the FSB will not have the same frequency as the DDR, but the DDR will work at a lower frequency.

    Now you may ask me where is the gain in that? well... now you can step by step increase the FSB to 170, 175, 180Mhz... and so on until you get CPU errors or overheating, and the DDR will eventualy reach 333MHZ again before you get instability. During that, you can increase the CPU voltage a little (0.1V or so, that is not dangerous).

    Before you overclock, you must get a really efficient CPU cooler and make sure that your chipset stays in earthly temps. as well. After you got the highest stable clock frequency, get the FSB back a few (5-10) MHZ because in somme other day, the room temp might be different and you might get instability as well. For example, if you reach 230 mhz stable, set it to 225 or 220 for maximum stability.

    There is another way to overclock, and that is if you have HighEnd DDR module/s, that can handle frequencies higher than the vendor specifies and that are build with overclocking in mind. (Corsair TWINX1024XLPT, OCZ, G.Skill, Kingston HyperX or sommething) and in this case you don't have to change the CPU/DDR ratio of 1:1 and this is the RIGHT WAY to overclock.

    I hope you got the ideea, and by the way I am a big AMD fan and I own a Athlon64 3200+ Venice that i have overclocked from 2000 to 2400 Mhz without even the smallest problem. Even so, i keep my CPU @2200 Mhz running 1:1 with a dual channel kit of Geil Value1024 RAM. I heard that overclocking the CPU can dammage it in time, and a highly overclocked CPU can crash after 3 monts, 1 year, who knows?

    You said that you had enough with AMD, well... think again, is the AMD CPU (the Athlon XP that you have is a great cpu by the way) to blame for your faulty system or the CHEAP components that you threw in?

    Everybody seems to complain about AMD systems that are instable but trust me when i say that the amd CPU is very stable, the instability commes from cheap DDR modules and motherboards that Intel clients with more $$$ tend to avoid.

    do somme reading before overclocking your machine and get somme good components for your CPU and it will Rock!

  4. Thanks for great tips.

    Changing FSB frequency gradually has been the original strategy.
    As far as I went with Slot A Athlon 750. increased voltage gradually to max 1.8 as I increased the FSB multiplier. Still, this only gave perhaps 5-6 extra minutes before machine was stuck in the eternal loop.

    As for components, I have been using the OEM Sims in past, however the machine I am using now got Kingston memory modules.
    The cooler I am using is Arctic cooler, which is neither cheapest nor most expensive. It is a good cooling system, and during overclock attempts the temperature been kept steady at max 55 degrees centigrade. Well, even without overclocking that was the temperature of the CPU.

    I will definetely give it a try again.
  5. don't get disheartened, I have overclocked 2 Athlons 2000+ 3200+, to about 10% (without having to adjust voltages), but I was too chicken to keep them there, worried about temp couldn't find decent limits and didn't trust the temp readings I was getting, but they worked fine for 2-3 hours that I allowed them to work.

    Just to say, it is possible, and the advice that has been given by the others is good solid advice, not that they need me to tell them or anyone that.

    I would say that you seem to indicate that you are increasing the voltage whilst increaseing the FSB, from what I understand you should get the FSB as high as is stable at normal volts, and then increase voltage, increasing the voltage increases the window of stability (until it all goes horribly wrong and you apply too much voltage). Applying higher volts without a higher FSB could have some strange effects.

    Not sure if I've got this right, but isn't the AGP frequency sometimes linked to the FSB speed, in which case could his graphics subsystem be conking out due to the increased speed.
  6. If it's your first time or one of your first times, don't expect to suddenly be able to turn your processor into some whizbang overclocker.

    Overclocking is a slow, methodical process, tweaking this and that until you find what works. You don't just set your FSB to the highest and shit your pants when it doesn't work.

    Personally I'm more than pleased with my AMD, although mine is not an older one like yours, it is a newer socket 939. If you look around, you'll see that a lot of the socket 939 AMD's overclock beautifully - some 3000+ Venice's (stock 1.8 GHz) do 3 GHz under the right conditions. I'm stuck with one that only does 2.8 GHz from stock 2.2, but I guess thats my fault for not getting an Opteron :)

    Happy overclocking, and if you need more information I recommend the following sites:

    www.dfi-street.com (even if you dont own a DFI motherboard its a good resource, lots of highly knowledgable people)

    You'd be silly to stop buying AMD's just because of this! The fact is, AMD's manhandle Intel in gaming at the moment. And that is all it takes to convince me to stay AMD...

    Sometimes you just get a bad chip! This may be your scenario...
  7. Quote:
    I'm stuck with one that only does 2.8 GHz
    You poor bastard. My heart bleeds. :wink:

    Damn I should've waited for the venice cores.... Mine's a winchester. :cry:
  8. Well, I tended to establish the threshold first, by setting the FSB as high as possible. As the system became unstable, I have methodically lowered FSB setting and tried to balance it well with the recommended voltage for the cores I got.

    But, if this: http://video.google.com/videoplay?docid=5393904704265757054 is overclocking an AMD chip, I definitely failed...
  9. Very good advice here I had fun reading this and yes ocing is a slow process, but once a person knows their system and what it can or cant do the process is easier.

    The looping sounds like a memory timing problem and the fsb, if you were able to increse the cpu mulitplier you would most likely find that the looping would end, it all has to do with timings.

    My cpu is unlocked but I did have an xp1800 that was locked and did have the looping problem but I unlocked it and sure enough the looping stopped when I incresead the freq.
  10. The ASRock K7VT6 is Socket A and can in theory support a 200MHz FSB (400MHz DDR).

    However if memory serves, a Socket A (462pin) 2600+ CPU would only be able to support up to a 166MHz FSB (333MHz DDR) when used in conjunction with PC2700 DDR SDRAM.

    IIRC only the Socket A Barton 3000+ and 3200+ had a 200MHz FSB (400MHz DDR).

    If you had a Barton 3000+ or 3200+ with a 200MHz FSB and PC3200 DDR SDRAM you would be able to run it at 400MHz DDR.
  11. Here is what I don't really understand.

    Call me a vegetable, but since the motherboard has 400Mhz FSB jumper and the CPU is 400Mhz, shouldn't I be able to set it to 400Mhz?
    As for the memory, both my DIMMs are 400Mhz and reported to run at 400Mhz.

    Your arguments do make a lot of sense. However, as I stated above I think I logically should be able to. That is if the products are as advertised...
    I miss the fine print stating otherwise...hmm...

    Is that none other than dirty sales tricks?
  12. What is the model number on your CPU?

    It should be AXA?????????? IIRC.

    Do you have a picture?

    Thanks :-)
  13. Hello,

    I think you should take a look at THG's CPU review chart. You will notice many AMD 64 CPU's are outperfoming even the best Intel CPU's at the current moment.

    Confused even more? Try Opteron 175 dual core 2.2ghz (2 x 1mb) vs. the X2 equivalent. What's the difference: Opteron's can OC much higher, lower voltage, runs cooler, runs faster and cost more. Of course, Opteron's have quality in them like the FX as they were originally for servers only.

    Or try this for added confusion: a 2.2ghz on AMD is equiv to 3 ghz on Intel

    Just because AMD's appear slower in speed than the Intel cpu's doesn't mean they suffer so much in performance.
  14. Quote:
    Changing the FSB back then was the only strategy to overclock. Intel had locked their multiplier ages ago while with Slot-A the only way to change the multiplier was to use the gold fingers.

    Ah the sad and agony days of Slot CPUs!

    I loved my slot 1 P2. All you had to do was cover those gold connectors and you could have your way with it. Great stuff.
  15. Will try to get a pic of the CPU as soon as I can.
  16. Quote:
    Call me a vegetable, but since the motherboard has 400Mhz FSB jumper and the CPU is 400Mhz, shouldn't I be able to set it to 400Mhz?
    You're a vegetable. :wink: That aside though, as I said above, your CPU isn't a 200Mhz/400DDR CPU. It will be either 133 (266) or 166 (333). They didn't make a 2600+ with that bus. It might be capable of running at that speed (probably would be if you could unlock the multiplier and lower it), but with that multiplier it would immediately start running at 2.3Ghz, which isn't likely to happen without more core voltage and probably better cooling too. Or your Chip might not even get there with that much effort.

    Stop expecting it to just work at 200/400.
  17. Hey I struck pretty good luck with overlocking my Athlon thunderbird. 38% stable overclockage with no volt mods or nuttin. Temps sitting round high 50's to 60 which isn't much of what it normally is at stock.
    Although I was using an older CPU with modern hardware. and Value RAM, kingston at that.
  18. I probably am a vegetable.. :D

    Here is the details of the CPU btw:

    AXDA2600DKV4D T83886A40949
    AQYFA0401WPMW (C)(R)1999AMD

    Well, with the reference to the Spitfire_x86's excellent CPU buyer's guide:

    2.0.13 Athlon XP (Barton)

    Known as: AXP "Barton"
    PR Rating: 2500+ (1.83 GHz), 2600+ (1.93 GHz), 2800+ (2.08 GHz), 3000+ (2.17 GHz)
    Platform: Socket 462
    Manufacturing process: 0.13µ
    FSB: 333 MHz effective (166 MHz DDR)
    Cache: 64k L1 instruction cache, 64k L1 data cache, 512k L2 cache
    CPU Extensions: MMX, 3D Now!, 3D Now! Extension, SSE

    Obviously, it is 333 Mhz. Still, only word coming to my mind is "WTF!" when the CPU box is labelled "400Mhz FSB!".

    Maybe you can get more info from the CPU information.
  19. http://www.tomshardware.com/2005/11/21/the_mother_of_all_cpu_charts_2005/page20.html

    The part number confirms that your CPU can only run at 333MHz DDR.

    The AXDA2600DKV4D runs at 1917MHz with a 166MHz FSB (333 MHz DDR) and overclocking it to 200MHz FSB (400MHz DDR) is going to be very challenging.


    Your best upgrade path is an nForce4 + AMD64 939 or nForce3 + AMD64 754.

    Semper Fi Linux on
  20. Well, there we go.

    I suppose everything has been clarified.
    Only one question remains - Why the hell stick 400Mhz fsb on the CPU package? Then again, the referral to the small print will probably come up.

    Nor sure I really want to go with AMD, especially after this.

    Big thanks to everyone posting in this thread. You have been very helpful.
  21. My Old 2500+ AXP Would Run At 2.2GHz With No Problems Without A Voltage Increase (Some Of Us Are Just Lucky I Guess 8) ) Now... Look A The OC On Mt Athlon 64 X2 (Look Below)
  22. Why Do You Always Put Capital Letters On Every Single Word You Write? It's Very Odd.

    But Anyway... The 2500+ was a 'sweet spot', because all it required was a FSB increase to get 2.2Ghz, which effectively turned it into a 3200+. Most would require a vcore bump as well though, but I'm sure later models where probably more refined and happy without one. The higher model ratings (with the 166/333 bus) all used higher multipliers that make an immediate jump to 200FSB less likely (if at all), because they would immediately be running at a higher clockspeed.

    But anyway...
    Why the hell stick 400Mhz fsb on the CPU package?

    No idea, that's definitely misleading if that's the original packaging. Just a packing cock-up I suppose.. *shrug*

    Nor sure I really want to go with AMD, especially after this.
    Hey, it's not like they've burned your house down or anything. AMD are currently the sensible choice for your average 'pooter. Especially if you're into a little bit of amateur overclocking. Prescotts are great for overclocking too of course, but managing their heat emissions make them a much more hands-on job in that regard.
  23. Hehe you can overclock the Prescott and use it to heat your house decently.
  24. LMFAO
  25. :D Little extre heat didn't hurt anyone yet.

    Well, I will see. I mean so far 5 weeks after the crash I still haven't uncovered all the failed components. Dead mobo, 2 200Gb disks, GFX card, PSU.
    Who knows if memory and CPU are intact.
    Don't see any point to continue replacing components on a Socket A build. And none of my friends run AMD systems so their recommendations are clear.
  26. Bahahahahhaahaha, (sorry dude so funny, is this a joke thread ?).... Awesome funny ;)

    You do you know how to unlock the CPU multiplier on the AthlonXPs right ?

    You raised your PCI/AGP bus to around 36/72 MHz, thats why your system became unstable (going from 750 to 800). You need to work so PCI/AGP stay very close to 33/66, the either the PCI : (base) FSB ratio divider would change at 100/3, 133/4, 166/5 and 200/6. (To keep PCI at 33 MHz and AGP at 66 MHz, otherwise = massive instability.... this is why only 'techs' overclock, it isn't meant for normal consumers). But a large die size Slot A Athlon's never overclocked 'that' well, unless the L2 cache ratio / timings where changed.... but I won't go there it is way beyond the scope of a forum. 'Triple checking' helps, but not without serious technical changes to the Slot A CPUs (L2 cache ratio and L2 cache latency to reiterate).

    This is why overclocking (using FSB) from say 133 to 160 doesn't work, but then using 166 does work again. (Basic maths and ratios my friend). Newever 'overclocker' boards can lock the PCI/AGP/SATA bus speeds to isolate them (more so) from instability.

    Never just expect overclocking to work, let alone be easy - Otherwise why grade / market different CPU speeds in the first place ?

    Do you even know how many MIPS (Million Instructions Per Sec) or MFLOPS (Million Floating Point Operations Per Sec) your AthlonXP 2600+ gets ?, do compare it to a '2.6 GHz' Pentium 4 some time (using say SiSoft SANDRA - from: www.sisoftware.co.uk). You might be disappointed with Intel for dis/similar technical reasons. Bear in mind most applications don't benefit from HyperThreading.

    Heck, just check Toms CPU Charts: http://www23.tomshardware.com/cpu.html

    [More serious now - sorry 'bout above, but it really needed to be said]

    Overclocking is for people more read up on hardware. Possibly yourself in the not to distant future. May I suggest the book "Upgrading and Repairing PC's - QUE - Scott Mueller" ?, I am sure now we've all had a good laugh you've got some pointers.

    Your AthlonXP PR2600+ is highly unlikely 400 'DDR' FSB, which is usually marked as 200 FSB in the BIOS btw (DDR remember ?). Chances are it is either 333 or 266 FSB as AMD never made a 2600+ with a 400 'DDR' FSB.... no, never. (Clock speed doesn't divide by 200 'DDR' equally, easy way to figure out ;) ).

    PR2600+ means performance rating roughtly equal to a 2600 MHz Pentium 4 (usually, but that isn't AMDs 'offical statement' regarding PR measurements, we all know).

    Sorry, too old for CPU Charts, (above).
    (Bookmark CPU Charts though and study it some time)

    So try here instead: :P

    Other pointers:

    Note: Usualy 333 FSB = 166 in BIOS, and 266 FSB = 133 in BIOS. As it is double pumped, like the Pentium 4 800 FSB (which is 200 QDR)

    I recommend books for the real meaty technical hints, you'll learn heaps before you know it, but there are other sources on the Internet for free. (eg: people above have covered it)

    Not sure which AthlonXP PR2600+ you've got either, there is a 266 FSB model and 333 FSB model. (Appears covered above, using the full CPU part number - OK)

    Just remember FSB in BIOS is usually half or quater of 'advertised' FSB, because of DDR and QDR.... and changing PCI/AGP bus speeds (they divide the base FSB speed to generate their clocks) by more than a few percent = major problems. You want to overclock the CPU, not your RAM or PCI/AGP bus. (Intel platforms are just as limited in this respect btw).

    Also remember there are boards (yours may have the option) which can lock the PCI/AGP/SATA bus speeds at 33/66/100 though, so changing the FSB won't suddenly make PCI bus hit say 37 MHz and make the system unstable. Overclocking is an art, an art requiring alot of math and a complete understanding of the 'entire' PC, especially the mainboard chipset and what every device is running at relative to each other.... not just cranking the CPU to a +20% overclocking and 'willing it to work'.

    Is your hardware OK ?, you may have damaged it with some of the overclocking 'attempts' you've tried I think. Avoid voltage increases until the overclock requires it. (Usually past 15% OC, which I'd avoid as a beginner until more read up on it, eg: How FSB, PCI/AGP, SATA, CPU, various multipliers / dividers which are present, and how each 'part' of the 'whole' generates their clock speeds. CPU's overclock well, but the PCI bus doesn't :P , as you likely noticed when the 'whole systen' screwed up)

    We'll make a tech of you yet though, don't worry :)
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