How to understand the result of "lshw", which CPU is in my PC?
 

hello there,
the result of "lshw" gives..
...
*-cpu
description: CPU
product: Intel(R) Pentium(R) 4 CPU 3.00GHz
vendor: Intel Corp.
physical id: 5
bus info: cpu@0
version: 15.4.1
serial: 0000-0F41-0000-0000-0000-0000
slot: XU1 PROCESSOR
size: 3GHz
width: 32 bits
clock: 800MHz
capabilities: boot fpu fpu_exception wp vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe constant_tsc pebs bts pni dtes64 monitor ds_cpl cid xtpr
configuration: id=0
*-cache:0
description: L1 cache
physical id: 6
slot: Internal L1 Cache
size: 28KiB
capacity: 28KiB
capabilities: burst internal write-through data
*-cache:1
description: L2 cache
physical id: 7
slot: Cache L2
size: 1MiB
capacity: 4MiB
capabilities: burst internal write-back data
*-logicalcpu:0
description: Logical CPU
physical id: 0.1
width: 32 bits
capabilities: logical
*-logicalcpu:1
description: Logical CPU
physical id: 0.2
width: 32 bits
capabilities: logical
*-memory:0
description: System Memory
physical id: 33
slot: System board or motherboard
capacity: 3GiB
...
I am not sure which processor I have (the housing, radiator is closed; so I cannot see the part number).
Pentium 4 (quite sure).
3.0 GHz: I see it in dmesg too.
15.4.1: is is this one?
wiki pentium 4 in http://en.wikipedia.org/wiki/List_of...icroprocessors
--->
Prescott 2M (90 nm)
Intel Family 15 Model 4
All models support: MMX, SSE, SSE2, SSE3, Hyper-Threading, Intel 64, XD bit (an NX bit implementation)
Intel VT-x supported by: 6x2 e.g. Model 662 and 672
Enhanced Intel SpeedStep Technology (EIST) supported by: all except 620.
Transistors: 169 million
Die size: 135 mm²
Steppings: N0, R0
<---
The reason of this question is: depending of the processor type, I should probably make a BIOS update of that HP compaq DC7100 .
The current BIOS version is 1.59 (20.9.2004).(extra slim model).
The latest BIOS version is 2.15A (14.8.2008):
=============== HP homepage =====================
http://h20000.www2.hp.com/bizsupport...kId=135&mode=5
=================================================
» Version: 02.15 Rev. A (14 Aug 2008)
Version: 02.14 A (3 Aug 2005)
Enhancements
Adds EIST runtime power management support for Intel 600 Series Processors.
Adds L2 Cache size of 2 MB to support Intel 600 Series Processors.
Adds microcode update for Intel E0, D0, and N0 stepping processors (F34, F41, and F43).
=================================================
perhaps I can increase the L2 cache with it?

Yes, you should definitely update the bios, there are always fixes and improvements. No, you can't increase your L2 cache it's built into the cpu package.
I wouldn't be too concerned with finding the exact cpu type, if you go by the manufacturer model and serial numbers you should be fine to pick the correct bios update.

You have an Intel Pentium 4 with 3 GHz clockspeed, SSE 1 and 2, Hyperthreading Technology, no 64 bit extensions and 1MB level 2 cache. This narrows down the choice to either the Pentium 4 530, 530J or 531. I was not able to determine the stepping of your processor, but since the BIOS contains microcode updates for several CPUs I would recommend to install it.