get front side bus info

vofka · 08-04-2010, 05:16 PM

Hello all! I need to know the fsb speed of my motherboard. I used dmidecode and lshw commands to view such information

Code:

[vova@vschenev /]$ su -c dmidecode
Password: 
# dmidecode 2.10
SMBIOS 2.4 present.
34 structures occupying 1428 bytes.
Table at 0x000FC200.

Handle 0x0000, DMI type 0, 24 bytes
BIOS Information
	Vendor: American Megatrends Inc.
	Version: 504    
	Release Date: 12/03/2007
	Address: 0xF0000
	Runtime Size: 64 kB
	ROM Size: 512 kB
	BIOS Revision: 5.4
	Firmware Revision: 161.10

Handle 0x0001, DMI type 1, 27 bytes
System Information
	Manufacturer: ASUSTeK Computer Inc.
	Product Name: F5R                 
	Version: 1.0       
	Serial Number: NF1S7961430182      
	UUID: 8032D268-C2A8-DC81-2585-001E8C72E319
	Wake-up Type: Power Switch
	SKU Number:                     
	Family:                     

Handle 0x0002, DMI type 2, 15 bytes
Base Board Information
	Manufacturer: ASUSTeK Computer Inc.
	Product Name: F5R       
	Version: 1.0       
	Serial Number: BSN12345678901234567
	Asset Tag: ATN12345678901234567
	Features:
		Board is a hosting board
		Board is replaceable
	Location In Chassis:                     
	Chassis Handle: 0x0003
	Type: Motherboard
	Contained Object Handles: 0

Handle 0x0003, DMI type 3, 21 bytes
Chassis Information
	Manufacturer: ASUSTeK Computer Inc.
	Type: Notebook
	Lock: Not Present
	Version: 1.0       
	Serial Number: CSN12345678901234567
	Asset Tag: ATN12345678901234567
	Boot-up State: Safe
	Power Supply State: Safe
	Thermal State: Other
	Security Status: Other
	OEM Information: 0x00000000
	Height: Unspecified
	Number Of Power Cords: 1
	Contained Elements: 0

Handle 0x0004, DMI type 4, 35 bytes
Processor Information
	Socket Designation: Socket 478
	Type: Central Processor
	Family: Pentium M
	Manufacturer: Intel            
	ID: EC 06 00 00 FF FB E9 BF
	Signature: Type 0, Family 6, Model 14, Stepping 12
	Flags://list of flags
	Version: Intel(R) Core(TM) Duo CPU T2250 @ 1.73GHz           
	Voltage: 1.4 V
	External Clock: 133 MHz
	Max Speed: 1729 MHz
	Current Speed: 1733 MHz
	Status: Populated, Enabled
	Upgrade: Socket 423
	L1 Cache Handle: 0x0005
	L2 Cache Handle: 0x0006
	L3 Cache Handle: Not Provided
	Serial Number: PSN12345678901234567
	Asset Tag: PATN1234567890123456
	Part Number: PPN12345678901234567

Handle 0x0005, DMI type 7, 19 bytes
Cache Information
	Socket Designation: L1-Cache
	Configuration: Enabled, Not Socketed, Level 1
	Operational Mode: Write Back
	Location: Internal
	Installed Size: 64 kB
	Maximum Size: 64 kB
	Supported SRAM Types:
		Other
	Installed SRAM Type: Other
	Speed: Unknown
	Error Correction Type: Single-bit ECC
	System Type: Instruction
	Associativity: 8-way Set-associative

Nothing about bus spead, the same output for lshw.
Is there some utilities to view fsb spead? In Windows there is a usefull utility as Everest or CPU-Z where i can see all info including bus spead.

GrapefruiTgirl · 08-04-2010, 05:41 PM

Given your processor make & model & 1733MHz speed there, Google says the FSB should be 532 or 533MHz; with the external clock at 133MHz and a rather normal multiplier of 4 (quad pumped), I'm inclined to believe it (though I'm open for correction!).

I don't recall ever seeing the FSB speed being shown by any Linux application that I've ever toyed with. However, you might be able to see it by entering the BIOS on your computer, if your laptop gives the option of setting the FSB or clock speeds yourself (or even seeing them) like desktops often do.

You already tried both my top 2 favorite tools for investigating hardware, but maybe the `hwinfo` tool would show something more? I've never tried it.

business_kid · 08-05-2010, 11:44 AM

IMHO you are going the wrong way about this. FSB is a mythical specification added to things because AMD painted themselves into a corner marketing wise back in the day, saying "Our next processor is going to have a 200Mhz bus". There is a related question: "When is a Mhz not 1 Mhz?" And the answer to that is rarely, as I hope I will show.

Your cpu says 1733 Mhz. That is actually 1733 Mhz, but that is driving the internals of the cpu. The cpu has a minimum of 4 clock cycles per single buyte (e.g. nop) instruction, and considerably more cycles for a multiply, for example. So the outside legs of the cpu will work at a max of 1733/4, or 433.25Mhz, and less in practice, because many instructions can be more than one byte. The 'stepping' in the bios is this 1733 divided down to a workable theoretical figure for the ram. It's actually done the other way around, the ram clock is divided up. Next is the Northbridge feeding to the ram, and a few cpu cycles get lost there. Then we come to pure marketing hype, the FSB speed, which is in fact the ram speed. The Bios actually says this usually. Take this box: It's an AMD Athlon 2.6Ghz which runs at 2.078, which everyone tells me is a Bios error because intel and amd count clock cycles differently.

They certainly do. Remember those P4s with a 532 Mhz bus speed. The logic was that is what a (wait for it) IBM XT(8 bit) machine would have to be doing. So in this case 532=532/4 or 133 Mhz Then with 200Mhz ram (32 bit) this became 800 Mhz or so. AMD carved them up with marketing stuff and Intel realised nobody believed those lies anyhow, so they started telling the same lies as AMD. AMD actually rate things on an IBM AT (16 bit). You are hearing of 1100Mhz bus speeds - divide that by four, because they claim those speeds for 64 bit machines. Ram just cannot go that fast yet. Also of course, there is the access time for ram. They are now inclined to be 6-1-1-1 or the like. This means that it takes 6 cycles to find an address once you change location, but it will serve you the next stuff fairly fast.

So which Mhz exactly did you want :-)).