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RedFred
09-12-2004, 05:02:48
I admit it. I am a computer moron.

I am looking at the new computers and they give two speed numbers. For example 3GHz and 800 MHz FSB. What the heck is FSB?

Thanks for your help.

Venom
09-12-2004, 05:05:06
Front Side Bus....I think it has something to do with processing CPU instructions....want more details...wait for SP.

Darkstar
09-12-2004, 05:44:27
Or Ash or Trip.

Or use Google. ;)

zmama
09-12-2004, 05:52:00
http://www.webopedia.com/TERM/S/system_bus.html

Sir Penguin
09-12-2004, 06:01:14
It's the speed (in pieces of data per second) at which the CPU communicates with the RAM.

SP

RedFred
09-12-2004, 20:40:19
Thanks for your help. No wonder it seems like I am always waiting for the bus.

I think I am still having trouble conceptualizing. Is the faster speed bogus because the CPU communicating with the RAM is the rate determining step?

Asher
09-12-2004, 21:06:50
It's not bogus, but ideally they should match.

A 800MHz FSB should use DDR400 memory (PC3200). The reasoning for this is a bit more complicated: the REAL frequency of the 800MHz FSB is 200MHz, it just uses "quad data rate" (QDR) to send data 4 times a clock, effectively 800MHz.

DDR400 is also 200MHz, but it uses "double data rate" (DDR) to send data 2 times a clock, effectively 400MHz.

So they're both running at 200MHz, and are in sync. So it's all good. No bottleneck.

RedFred
10-12-2004, 20:40:26
Hmm. It is all going dark and hazy...

Can you explain a bit about why the first speed number might be important - in English if possible.

zmama
10-12-2004, 20:53:55
If you are asking what I think you are...the first number is the speed of your processor.

In GENERAL the faster the processor the better. I'd be very happy with a 3 gig processor :)

zmama
10-12-2004, 20:59:37
And a fsb speed of 800mHz is very quick.

As far as I know as good as you can get for home...I'm qualifying that because I haven't looked at new stuff in a couple of months.

Venom
10-12-2004, 21:02:21
If it's not the fastest, it's way up there. Especially for standard, store bought type machines.

zmama
10-12-2004, 21:06:21
Yeah i'd love to have it!! I'm reduced to a 400mHz PII with 224 mb mem running Win 98 :(

:cry:

Sir Penguin
10-12-2004, 21:52:39
I think they've got 1066 MHz FSBs, but I'm not sure.

SP

Asher
11-12-2004, 03:36:35
Originally posted by RedFred
Hmm. It is all going dark and hazy...

Can you explain a bit about why the first speed number might be important - in English if possible.
Which first speed number?

The 3.2GHz means the processor runs at 3200MHz. This is fast.

The 800MHz means the processor talks to the memory and system components 800MHz. This is fast.

Asher
11-12-2004, 03:39:19
Originally posted by Sir Penguin
I think they've got 1066 MHz FSBs, but I'm not sure.

SP
I think that's only on the 3.46GHz Extreme Edition right now.

Nav
13-12-2004, 17:07:47
I Ghz FSB'? Well I'll be blown....

RedFred
14-12-2004, 01:34:52
Look guys... can you draw me a picture or use a simple analogy... you know like the CPU is the brain and the RAM is the ______...

Remember I said I was a computer MORON. Thanks again.

Darkstar
14-12-2004, 01:43:25
RAM is the cognitive memory (that is, your ability to remember multiple things at once).

Your Hard Drive is like your long term memory.

Sir Penguin
14-12-2004, 01:56:40
A Front-Side Bus is just what its name says: a bus. An 800 MHz bus system can carry 4 passengers per bus, and busses travel between the industrial district (the CPU) and the residential district (the RAM) 200 million times per second.

SP

Asher
14-12-2004, 02:02:38
Sometimes it doesn't carry 4 passengers, but less. ;)

Sir Penguin
14-12-2004, 02:37:06
That's why an 800 MHz bus system can carry 4 passengers per bus. :)

SP

Asher
14-12-2004, 07:05:53
Isn't that more of a car, then?

Also, I don't think that's correct anyway.

Memory busses tend to be 64-bit these days. So they would carry 8 passengers per bus, or 64 (depending how you count passengers).

;)

Edit: But now I see you're talking about QDR, not how many bytes are sent at once.

Sir Penguin
14-12-2004, 07:55:50
They're short busses.

SP

zmama
14-12-2004, 15:28:39
CPU=brain
RAM=short term memory
Hard Drive=filing cabinet
FSB=superhighway between brain and short term memory

Venom
14-12-2004, 16:31:04
800Mhz FSB=4 lane superhighway

Asher
14-12-2004, 17:17:26
1066MHz FSB=4 lane superduperhighway

Venom
14-12-2004, 17:27:56
A 4 lane superhighway with a higher speed limit and possibly HOV lanes.

RedFred
17-12-2004, 05:29:18
Hmm. So the bus speed is more important than the other speed with the higher number?

DevilsH@lo
17-12-2004, 07:00:59
They are both equally as important, the bus speed will determine the transfer of instructions and data between working memory and the processor, the processor speed will determine how quickly results from those instructions can be determined which will then be shunted back off across the bus to the memory for use later. In reality registers and stacks and all the other processor complications are involved in the actual production of results and an output, but that's it in it's most basic form.

Deacon
17-12-2004, 08:56:03
CPU and FSB speed are both important. Though CPU MHz depends in part on FSB MHz, a low multiplier and/or poor efficiency will still hurt a CPU with high FSB MHz.

RedFred
21-12-2004, 04:25:41
Thank you.Those last two replies seemed actually helpful.