Asus A7A266 Owners and Smart People

[chris_y2k_r1]

I am a bit confused. In the bios for my A7V266 mobo, there is of course, a multplier and the Frequencies. Currently I have them set at 11.5x133/33. What I don't understand is that this is a 200/266 MHZ FSB board. Why does the frequency range only go up to 145 or so? How are they getting the 266 FSB speed?? I realize that with DDR, 133 is getting hit twice on each cycle so that makes sense but I don't see how that would apply to the FSB. Also, what does the 33 respresent? I'm confused. Thanks!!


Oh - For what it's worth, I have an AMD 1.4 Athlon in there and it's running at 1533 MHZ. Not much OC'ing but some Very stable.

Also, while we are at it. This computer will only run PC2100. Which I have in there - A Samsung PC2100 DDR Stick. However I cannot get the timings any lower than 2 3 3 7 or it just crashes.. Any suggestions on what I can do or what memory I could use that's cheap.. cheap.. cheap!!! I would think that I could get a good deal on PC2100. Thanks my fellow geeks!!

Thanks Guys!

[sm8000]

DDR = Double Data Rate

Therefore 133 doubled is 266.

[deadkenny]

As mentioned, the true underlying bus speed is 133Mhz. The term 266 is somewhat inaccurately applied since there are 2 signals per clock cycle. The 33 is the PCI bus speed (33MHz).

[chris_y2k_r1]

Originally posted by deadkenny
As mentioned, the true underlying bus speed is 133Mhz. The term 266 is somewhat inaccurately applied since there are 2 signals per clock cycle. The 33 is the PCI bus speed (33MHz).

Ok the 33 I understand, that makes sense. However, this board does not support DDR (A7V133) so the doubling does not apply here.

So I guess my question has evolved, since the FSB does not include the PCI slots, what does the FSB actually do or 'mean'. Also, is the FSB running at 133 MHZ in this case, even though they say it's a 200/266 motherboard.

I remember reading a post by you before deadkenny, but I didn't quite understand what you were saying. How do they come to 200/266 and why do you say it's really 133???

Thanks.

[chris_y2k_r1]

Originally posted by sm8000
DDR = Double Data Rate

Therefore 133 doubled is 266.

I addressed that in my post - this Mobo doesn't support DDR and in addition, I wasn't asking about the memory speeds, I was asking about the FSB.

Thanks!!
Chris

[sm8000]

Well, what the hell board ARE you talking about???

Thread's title says A7A266.

First line of first post says A7V266.

Now you say A7V133???

FSB = Front Side Bus. Channel between CPU and RAM. The memory speed comes into play here - how fast it can transmit on this bus(100, 133, etc.). Same with the CPU's FSB speed.

Some FSBs, when overclocked, will overclock the PCI bus too. Depends if the board has a "PCI Lock", same with AGP.

[werz]

The A7A board I had took both DDR and SDRAM but only one type at a time and had to have the CMOS reset if changed.

[chris_y2k_r1]

Sorry for the confusion.. I am working with two mobos. One is an A7A266, the other is a A7V133. My brain keeps getting them cross wired.

The board in question is an A7V133.

Here's what I don't understand... there are two buses. One inside the CPU. This must be the front side bus. Then there is another bus outside of the CPU that connects the CPU's bus to the mobo bus and thus the memory etc...

If my motherboard says 133 MHz External Bus Speed, which bus does that refer too (I actually think it's the backside bus) and how are the speeds of the buses controlled?? How do they get 266 MHz bus speeds when the BIOS clearly states 133 MHz??

[sm8000]

I'm not aware of any bus inside a CPU. The external bus is the frontside bus. The ONLY bus between the CPU and RAM. I'm not aware of any backside, or other, bus.

If you see a 266MHz FSB, then the hardware is DDR-capable. The true speed is 133MHz, just twice as much data per transfer. Marketing people decided to imply the clockrate itself was doubled rather than the datarate. Hence 266 where it's really 133.

In BIOS, if you can set your FSB to 133 on a DDR board, you can use 266 RAM. 166 = 333, 183 = 366, 200 = 400, etc.

[chris_y2k_r1]

Originally posted by sm8000
Well, what the hell board ARE you talking about???

Thread's title says A7A266.

First line of first post says A7V266.

Now you say A7V133???

FSB = Front Side Bus. Channel between CPU and RAM. The memory speed comes into play here - how fast it can transmit on this bus(100, 133, etc.). Same with the CPU's FSB speed.

Some FSBs, when overclocked, will overclock the PCI bus too. Depends if the board has a "PCI Lock", same with AGP.

Yeah - my bad. I am working w/ two boards; An A7A266 and an A7V133. The board I am speaking of is an A7V133 - this is the board in question. My bad!!!! Doh!

So, I guess to focus back in on the question - How are the bus speeds controlled (Front and Backside bus) with the BIOS says 133 MHz. How is it that the FSB is running at 266 then?

Also, The FSB is actually located INSIDE the CPU, correct?

[chris_y2k_r1]

Originally posted by sm8000
I'm not aware of any bus inside a CPU. The external bus is the frontside bus. The ONLY bus between the CPU and RAM. I'm not aware of any backside, or other, bus.

If you see a 266MHz FSB, then the hardware is DDR-capable. The true speed is 133MHz, just twice as much data per transfer. Marketing people decided to imply the clockrate itself was doubled rather than the datarate. Hence 266 where it's really 133.

In BIOS, if you can set your FSB to 133 on a DDR board, you can use 266 RAM. 166 = 333, 183 = 366, 200 = 400, etc.

OK OK - That makes some sense.

I guess since when I look at CPU specs - they spec a front side bus speed on the CPU itself, I figured the bus must be in the CPU?! That's what I was thinking.

The specs on this mobo are FSB 200/266 but the memory slots only support standard SDRAM and not DDR (They are different memory slot styles)


Please bare with me, I am beginning to grasp what you are saying.

[sm8000]

I'm starting to get it too - the board can take an Athlon (200/266) or a Duron (200) but only SDRAM (PC-100 or -133). So for that board (or any board with 133 in its name) you need not worry about DDR. The FSB speed will be 133, provided your hardware is capable of that speed and is set to do so in BIOS.

The CPU's FSB spec just means what speed FSB it is capable of running on. The bus is on the board.

[chris_y2k_r1]

Originally posted by sm8000
I'm starting to get it too - the board can take an Athlon (200/266) or a Duron (200) but only SDRAM (PC-100 or -133). So for that board (or any board with 133 in its name) you need not worry about DDR. The FSB speed will be 133, provided your hardware is capable of that speed and is set to do so in BIOS.

The CPU's FSB spec just means what speed FSB it is capable of running on. The bus is on the board.

OK - That makes sense. And I agree with you on that one.

I am still abit unsure of your assertion that there is not an internal bus. Again, please don't think I am arguing here - just trying to get it right. A better understanding of this stuff will allow me to better configure my/a system.

In the manual for the motherboard the author specifies; I will quote them. This comes from "Motherboard Features":

"Stepless Frequency Selection: Allows CPU external (FSB) frequency setting to be set in 1 MHz increments or reduction."

Since they specify external - it sounds like there is an internal bus. However, since the manual also reads: "external (FSB)", it seems to me that they are saying same as you, the FSB (as we know it) is the bus speed of the mobo and not the CPU. Does that make sense/you agree with that? There must be an internal bus but no one really speaks about it, otherwise they would not specify "external". Ya dig?

[sm8000]

Okay yeah, there is an internal CPU bus, but not one we can do anything about and therefore we shouldn't worry about. For our purposes there isn't

[chris_y2k_r1]

Originally posted by sm8000
Okay yeah, there is an internal CPU bus, but not one we can do anything about and therefore we shouldn't worry about. For our purposes there isn't

Cool, *Plugs Ears* Lalalalalalalalalalala




Have a good Holiday!!