A7V (KT-133) bus speeds?

Hello,
I'm new to this forum, and I was hoping I could pick the minds of a few of you "more experienced" guys.
I have an Athlon T-bird 1.1 ghz processor, Asus A7V rev.1.02 w. dipswitches, BIOS 1004d.
I am running the system in "jumper-free mode", and my system bus clock at 100 mhz. Is there any way to know if the multiplier on my T-bird 1100 is locked or unlocked? I contacted my retailer and was told that they could NOT give me that information because their contract with AMD prohibited them from doing so. But what I do with MY equipment, FOR MY OWN PERSONAL USE, is my business. I know some of the risks involved with tampering with my processor.
Do any of you run your system at the higher BUS speeds? I guess when I bought these components, I just took it for granted that the KT-133 meant that I would be running my Sys Bus speed at 133, and my SDRAM at 133. That's why I bought the PC-133 anyway. I have tried setting the SDRAM clock speed to 133(asynchronous), and the system is still stable, but is it better to run it this way?
Also, if my processor is locked at a multiplier of "11", and I want to run my sys bus clock at say 133, could I change the multiplier to say.. "8" or "8.5" and still hope to have a fast, but stable, system? I know the Athlon processor runs at a Bus of 200 mhz even when my system bus is at 100. I hope a few of you might have some experience and advice that you can share with me. I don't really want to overclock my T-bird for now, just increase the sys bus speeds.
Thanks,
Phil
Corpus Christi, TX
11 answers Last reply
More about speeds
  1. ok, i'll speak from my experience and from what others seem to be saying. you are correct in saying that while the fsb is technically 100mhz, it is a ddr bus so it is an effective 200mhz. now, the kt133 chipset has the ability to run the fsb and the ram bus at different speeds at the same time. therefore, the right way to do it (before an attempt to overclock) is to run the fsb at 100mhz (effectively 200mhz) and the ram at 133mhz. remember, when you increase the fsb, you also increase the pci clock. so, if you run the fsb at 105mhz (effective 210mhz), the pci bus will run at approximately 35mhz (which is within reason). since the fsb id 'double pumped', it is more sensitive to fsb changed. the general consensus is that the kt133 platform will run ok at UP TO 110mhz (effective 220mhz), although i wouldn't bank on getting it higher than 105mhz. now, to throw a twist in, the ram clock is only really set at 133mhz if the fsb is 100mhz. the way the kt133 chipset does it is to add 33mhz to the host clock, which is 100mhz (which i keep reminding you is ddr). therefore, if you overclock and set the fsb to 105, for instance, you are really running the ram at 138mhz which might be too high for generic pc133 modules. i hope this wasn't too confusing. i'm just trying to show how the pci and ram buses are affected by playing with the fsb. now, you ask whether you can lower the multiplier and run the fsb at 133. i tried it because it seemed reasonablt to me. what i did (which my mobo allows for) is set the fsb to 133 and the pci clock to 33 and left the ram clock set equal to the host clock of 133. needless to say, it didn't work. the computer wouldn't post. it would seem that the current cpu's ican handle the ddr 200mhz, and with some overclocking, they can sometimes handle up to around a ddr 220mhz. that would be why the different cpu's are coming out to hande the effective 266mhz fsb. whew...did that make sense? ok, as far as the multiplier being locked, this has to do with the L1 bridges. i would bet yours is locked but you can unlock it with as little as a #2 pencil (that is what i did to my 900, but if you look around there are people who describe some better methods). look at your L1 bridges, they are little dots or lines at the top of the cpu. if they look like this, :::: , they are not connected and you cannot change the multiplier. take a sharp pencil and draw a nice line connecting the top and bottom dot to get it to look like this, |||| , and if you mess up and cross the dots, use the eraser and some alcohol to clean it and try it again. ok, that was long winded, hope it helps. if i got too confusing or if i just talked in circles, let me know...
  2. there's a japanese guy that replaced a PLL on one of the newer DDR motherboards (the 133FSBx2=266 kind) and got it to run at 166x2=332Mhz with an _older_ processor than the new ones designed for DDR. what that means is the processor is not the problem here, it's something with the boards... makes me wonder what AMD got the board manufacturers to agree to...? I'd do this mod, but the new PLL was US$100, and I'd risk frying something. as it is, my ata/100 drive is pretty buggy, trying to run it at 133x2 might be hard.
    (at the moment, my computer won't even detect that drive, and I haven't changed a thing... just tested out an AGP card, removed it and put in my old PCI card, and whammo bango, the drive that I had working for a few weeks suddenly stopped being detected for no reason I can think of.
    back to your problems though... the a7v lets you run the memory at "100" or "133" at the 100x2FSB speed. when you crank it up, it tries to crank up the speed of the memory too, so if you ran your FSB at 133x2, it would be trying to run the memory at around 177(33% faster than 133). I haven't seen any memory yet that would handle this, but I think maybe FSB's of 115-120 might be possible after the PLL mod. anyway, that's my $.02
  3. Hello ledzepp98 (cool name!)
    Thanks for your help. You made this whole mess a little easier to understand.
    In my BIOS, it states that if I increase my BUS higher than 120 mhz, the PCI BUS freq will be cut to one-fourth. So at 133 it would still be at 33 mhz. I realize now that the CPU is really the limiting factor here, But I just didn't know the 200 mhz BUS that's always talked about is really the 100 mhz BUS carrying the double data that Athlons carry. My T-bird is really fast now, and I don't have any plans to overclock, and YES, those bridges are all open on my chip. I took the time to write down all the info before installing it.
    Can I pick your brain once more? Let's say (hypothetically) that I could increase my BUS to 133 and my PCI was running at 33.25 (one-fourth that speed), what would it do to my AGP speed? Isn't that a multiple of something? I cannot remember where I saw that at. I know some video cards can run stable at higher speeds, but some can't. This is all very interesting. Thanks for your help..
    Phil
  4. Hello tmbg,
    Thanks for your $.02 worth. IOU 2 cents..or is that 2 cents X 2? lol..
    Let's say we could crank the FSB up to 133 mhz, isn't there still the option in the BIOS to allow us to run the SDRAM at that frequency? Right now I have the option of running my memory at 100 or 133 mhz(synch and asynch, right?). Theoretically, if cranked my FSB up to 133, my PCI Bus would be cut to one-fourth (33.25), and one could run their memory at 133? The multiplier on the CPU would have to be changed of course, but what would all of this do to the AGP speed? I've already asked this question to ledzepp, but I'm wondering if I could hear your ideas as well. I guess all this wondering is limited to how fast the T-bird would run, right? Thanks for your help. I really appreciate it.
    Phil
  5. as far as the agp speed, i believe it is also linked to the pci speed (although maybe tmbg could help here also) except there is a multiplier (as in 2x or 4x speed). therefore, if the pci speed is 33mhx, the agp slot would run at 66mhz for a 2x slot or 133mhz for a 4x slot. any deviation from the 33mhz pci speed would have an effect on the agp speed (by a multiple of 2x or 4x). as far as running the fsb at 133mhz (effective 266mhz) and the dram clock egual to the core clock (therefore also 133mhz), with a pci divider of 1/4 (therefore running the pci slots at 33mhz), it seems like it would work in theory. all i know is that i tried to do that exact same thing and the computer would not even post. again, i think it is the current cpu that can't do an effective 266mhz (despite the earlier post that said it might be possible). and just in case you were wondering, i did lower the multiplier to run my 9x100 processor at 6.5x133 (which would actually underclock it).
  6. Thanks alot for all your help. I appreciate you taking the time to help me figure this stuff out. I really do find it fascinating.
    I will leave my system running the way it is for now, and if i happen on any useful info, I'll send it your way.
    Phil
  7. regarding the multiplier lock or unlock you can easily check your processor on it's L1, if there look like IIII then it unlock, if it looks like :::: then it's lock. if you have a lock CPU all you have to do is, connect the dots, to look like IIII. after unlocking the multiplier then you are able to OC the multiplier.

    regarding the FSB oc, on your A7V board, you probably can't get anyhigher than 110, if you are lucky 107. but the memory you can set it to 133 with a FSB 100. I'm using Abit Kt7 board, i control all the OC, everything from the bios, including the memory speed. I'm not sure where you would set it up for a7v, but search around for a "TWEAK A7v" on the internet. there should be some information on what everything means on the a7v bios.
  8. Thanks for the reply,
    For now, I think I'll stay put. My system is running very stable, and I feel better knowing all of this. Thanks for clearing up the thing about the L1 bridges. I wasn't sure if there were any others that needed to be messed with just to unlock the multiplier.
    Phil
  9. depends on your BIOS. the Asus A7V will crank up the memory speed whenever you crank up your FSB. so if your FSB is say, 110 (like mine), your mem ends up running at a little over 140 (I forget exactly, somewhere around 146). that's fine if you have very good pc133, or better yet, pc150 ram. on other boards, like the Abit KT7, you can run almost all of the busses independantly, so the PCI will always run at 33, regardless of what you run the FSB at. however, the FSB and mem are sort of tied to each other through the northbridge of the chipset. it would be really nice though to be able to run slow memory and a fast bus. sigh.
    good luck!
  10. Thanks tmbg,

    I agree. The Asus A7V will indeed crank up the memory speed if you increase the bus speed, but one still has the option to run their memory at the same speed as the BUS. So, in theory, If you could get the Athlon T-bird to run stable at the double multiple (DDR) of the FSB, then a person wouldn't have any problems with the rest of the system. Like for instance if you happened to buy one of AMD's newer T-birds that is rated up to 266 mhz. Even though that processor is mainly for the new generation of DDR motherboards that are showing up, a person could put one in their A7V, crank the FSB up to 133, run their memory at 133, and still keep their PCI and AGP speeds the same. At least in theory, right? As a matter of fact, wouldn't these NEW processors have their multiple locked at the multiple of the higher BUS speed in the first place? I mean... wouldn't they have to to do that to have any performace gains over the 200 mhz BUS they run at now?
    Something to think about.
    Thanks for the reply..
    Phil
  11. i would hope so...it would be nice to keep my mobo and just get the new chip. all i would have to do is set the fsb and pci to 133 and 33 respectively, then just run the ram at the cpu clock of 133.
Ask a new question

Read More

CPUs Bus Processors Overclocking