X2 overclocking problem...

[Cromewell]

Yes, the FSB is 4x the bus speed on any Intel CPU thats not extremely old.

On the Pentium 4 Northwoods, it has an FSB of 400Mhz and a bus of 100. So 100 x 4 = 400Mhz FSB

On the newer P4's and Pentium D's, they had a bus speed of 200 and an FSB of 800. So 200 x 4 = 800Mhz FSB.

On the Core 2 Duo's, they have a bus speed of 266.5Mhz, and an FSB of 1066Mhz, so 266.5 x 4 = 1066Mhz.

Really Cromewell, you should know better :rolleye:

Maybe you should? The FSB runs at 100MHz, 200MHz, 266MHz, nMHz and has an effective speed of 4x that because it is quad data rate.

The CPUs clock speed is derived by multiplying the FSB by the CPUs multiplier. So lets take a look at what we get by doing some math:
665.0MHz * 11.0 = 7315MHz....a bit much don't you think?
266.3 * 11.0 = 1829.3MHz...hey looks good

So either CPU-Z read the P4 Northwoods wrong, or it's reading all the current processors incorrectly.

It's just a terminology thing, it's calling the quad-pumped speed the rated FSB, which it sort of is. It's not saying the FSB is that speed, it's saying that it is effectively running that speed.

 

[StrangleHold]

I know people hate the car comparison, but Cromewell is right. Say you have a effective bus of 800mhz its really 200mhz. Its like if you have a 1 lane road and the speed limit is 200mph, you turn that road into a 4 lane and the speed limit is still 200mph, you can say you have a effective speed of 800mph but no car is traveling over 200 mph. So the true speed limit is still 200mph!

 

[Dual_Corex2]

I know people hate the car comparison, but Cromewell is right. Say you have a effective bus of 800mhz its really 200mhz. Its like if you have a 1 lane road and the speed limit is 200mph, you turn that road into a 4 lane and the speed limit is still 200mph, you can say you have a effective speed of 800mph but no car is traveling over 200 mph. So the true speed limit is still 200mph!

No offense, but that was a horrible analogy LOL.

 

[StrangleHold]

Like I said people hate the car comparison but its simple

 

[Geoff]

I know people hate the car comparison, but Cromewell is right. Say you have a effective bus of 800mhz its really 200mhz. Its like if you have a 1 lane road and the speed limit is 200mph, you turn that road into a 4 lane and the speed limit is still 200mph, you can say you have a effective speed of 800mph but no car is traveling over 200 mph. So the true speed limit is still 200mph!

That didnt help at all. We already knew that Intel quad-pumps their CPU's. What we werent sure of was whether it was FSB x 4 = bus, or bus x 4 = FSB.

 

[Cromewell]

That didnt help at all. We already knew that Intel quad-pumps their CPU's. What we werent sure of was whether it was FSB x 4 = bus, or bus x 4 = FSB.

No? It's exactly the right way to think about it, it says that FSB x 4 = bus.

Hmm... what was the original question again?

 

[StrangleHold]

That didnt help at all. We already knew that Intel quad-pumps their CPU's. What we werent sure of was whether it was FSB x 4 = bus, or bus x 4 = FSB.

What do you mean it didnt help, 200mhz is your FSB speed, 800mhz is your effective bus speed

 

[hermeslyre]

If it hasn't been mentioned you should make sure your PCI bus is locked (if that's possible with your motherboard) An unlocked PCI bus can cause problems with ones hard drive, or so i've heard.

 

[Dual_Corex2]

I think ill just give up on overclocking. I never notice a huge performance increase anyway, only in benchmarks.

 

[Geoff]

No? It's exactly the right way to think about it, it says that FSB x 4 = bus.

Hmm... what was the original question again?

What do you mean it didnt help, 200mhz is your FSB speed, 800mhz is your effective bus speed

It didnt help because you never specified which was the FSB and which was the bus speed.

For all we know, you were using that analogy to say that the bus speed is 4 times that of the FSB, or that the FSB is 4 times that of the bus speed.




So basically what your saying is that CPU-z and processor makers are getting FSB and Bus Speed mixed up?

 

[Cromewell]

So basically what your saying is that CPU-z and processor makers are getting FSB and Bus Speed mixed up?

No. We are saying CPUz is using misleading terms.

Bus Speed: The speed of the bus that connects the processor to main memory (RAM). As processors have become faster and faster, the system bus has become one of the chief bottlenecks in modern PCs. Some examples of bus speeds are 1066 MHz, 800 MHz, and 533 MHz.

Notice it doesn't say 266MHz, 200MHz or 133MHz

 

[StrangleHold]

All it comes down to is the FSB speed is 200mhz and its Quad pumped. It can send and receive a signal 2 times pre cycle plus transfer 2 bytes of data at once that gives you your effective Bus speed of 800mhz, but the true FSB speed is 200mhz.

 

[Geoff]

All it comes down to is the FSB speed is 200mhz and its Quad pumped. It can send and receive a signal 2 times pre cycle plus transfer 2 bytes of data at once that gives you your effective Bus speed of 800mhz, but the true FSB speed is 200mhz.

We are not arguing about how the speeds are determined or how they work, but rather trying to get the terms FSB and Bus Speed figured out.

 

[Dual_Corex2]

The Front Side Bus, is the ultimate speed of the processor. Its the core frequency at which every other component will operate at. It effects the hdd, PCI cards, AGP, RAM, and so on. Since AMD no longer uses a "Front Side Bus" they use Hypertransport. But they still have a core frequency at which everything operates at, and that is still your basic mhz speed.

The effective speed of the processor, the external clock, your ghz. I believe this is just the speed at which the processor can process incoming data. It will not have an effect on your other hardware, just the CPU. Basically, if you have a high external clock, like 3.6ghz but your core clock is only 100mhz, your computer wont seem or be as fast as a computer with 3.6ghz and 200mhz.

And your bus speed, is basically the effective speed of your front side bus, or now in AMDs case, the hypertransport. However this is not your TRUE front side bus.

Its like the RAM ratings. DDR400, only running at 200mhz but has an effective speed of 400mhz since its double data rate.

Its like best buy selling car audio. They dont advertise the RMS ratings, which are more important, but instead the MAX ratings. When you buy that "1100watt max" dual subwoofer setup, sure the big number sounds good but in the end its just a number. It wouldnt be anything put against an audio system thats 1100watts RMS.

 

[Geoff]

Besides your first paragraph, you are basically saying what StrangleHold has been saying, which brings me back to the point where we know the FSB and bus speeds are determined and such, but we were getting the FSB and Bus Speed term confused.

 

[StrangleHold]

We are not arguing about how the speeds are determined or how they work, but rather trying to get the terms FSB and Bus Speed figured out.

I dont get what you dont understand, your (true FSB) is 200MHZ. Your effective (bus) is 800MHZ. There nothing on the bus that is going any faster than 200MHZ. The word (effective) as in 800MHZ is just a marketing scheme. Intel and AMD both did it. They can say 800MHZ all day long but there nothing running any higher than 200MHZ. I mean they can print that it is a 800MHZ FSB instead of sayin its the bus but it changes nothing!
If they said the FSB is 800MHZ thats misleading, thats why they use the word effective. I mean you could even use the word 800mhz FSB instead of just bus as long as you say (effective)