| View previous topic :: View next topic |
| Author |
Message |
Marcin
Joined: 02 Jan 2005
Posts: 8519
Location: Poland
|
 Posted: Mon Nov 06, 2006 4:57 pm Post subject: Strange Nexgen |
 |
|
This CPU is on my way and I don't have picture of bottom. First time I see so strange Nexgen P90. Somebody can tell what 4.5 could means ?
_________________
Visit ABC CPU - Virtual CPU Museum. |
|
| Back to top |
|
 |
g0b
Joined: 18 Jul 2006
Posts: 1385
Location: France
|
| Posted: Mon Nov 06, 2006 6:41 pm Post subject: |
|
|
Hum.. Don't know, but I have a P100 that also have "4.5" next to the P-Rating
g0b |
|
| Back to top |
|
|
Blackfury
Joined: 11 May 2006
Posts: 147
Location: DK
|
| Posted: Mon Nov 06, 2006 7:37 pm Post subject: |
|
|
the clock set at x 4.5 maybe 20mhz x 4.5 = 90MHZ
and 25mhz x 4.5 = 100MHZ
Maybe 
_________________
VIA C3 Processor Forever |
|
| Back to top |
|
|
Marcin
Joined: 02 Jan 2005
Posts: 8519
Location: Poland
|
| Posted: Tue Nov 07, 2006 1:44 am Post subject: |
|
|
| chiptalk wrote: | It is probably the rev mask or something. I have seen 4.0, 4.2, 4.5 etc. I think E is 5.0.
Anyways, I have one just like that in my collection of NexGens. Very nice chip. Congrats. |
Please update your collection site ! At first Nexgen section 
_________________
Visit ABC CPU - Virtual CPU Museum. |
|
| Back to top |
|
|
g0b
Joined: 18 Jul 2006
Posts: 1385
Location: France
|
| Posted: Tue Nov 07, 2006 3:09 am Post subject: |
|
|
| Blackfury wrote: | the clock set at x 4.5 maybe 20mhz x 4.5 = 90MHZ
and 25mhz x 4.5 = 100MHZ
Maybe |
I don't think so. The P90 has a x2 clock multiplier. (42 MHz bus speed, 84 MHz core)
g0b |
|
| Back to top |
|
|
mtx500
Joined: 21 Nov 2003
Posts: 117
Location: Nuremberg, Germany
|
| Posted: Tue Nov 07, 2006 7:17 am Post subject: |
|
|
| g0b wrote: | | The P90 has a x2 clock multiplier. (42 MHz bus speed, 84 MHz core) |
Definitely! All NexGen CPUs have a fixed x2 multiplier!
(That is between the CPU core and the front side bus (the NexBus). In the chip set, there are additional clock reductions: between the NexBus and the VL or PCI bus and between VL or PCI bus and the ISA bus.)
And it's also not the mask revision. The mask revision is the last digits of the first line of the ID string, in this case 202, which means revision D1 according to Christian Ludloffs 80x86.cpu document (available here: http://grafi.ii.pw.edu.pl/gbm/x86/4P_V330.ZIP).
I've seen this printing before, and I always thought it is the voltage rating. Yes, I know, there is "4.0" in the ID string which according to the documentation means 4.0V, but I have no other explanation. I've never seen something other than 4.0 in the printed ID string.
I think all Nx5x86s are planned to run at 4.0V. Maybe this part failed 90 MHz, and instead of selling it as 80 MHz part which was not what the market required they re-certified it with a higher voltage to achieve 90 MHz.
Note that on the NexGen PCI board, there is a resistor plugged into JP22 (between pin 2 and pin 3) which I suspect determines voltage. All the boards I have checked have a 1.6 KOhm resistor here.
So it might be that this CPU runs at 90 MHz only in PCI boards set to 4.5V core voltage. |
|
| Back to top |
|
|
Marcin
Joined: 02 Jan 2005
Posts: 8519
Location: Poland
|
| Posted: Tue Nov 07, 2006 10:33 am Post subject: |
|
|
| chiptalk wrote: | I still owe mtx500 about two dozen photos/text descriptions for his site.  |
Me too hehehehe 
_________________
Visit ABC CPU - Virtual CPU Museum. |
|
| Back to top |
|
|
|
![[ Hidden ]](https://cdn.cpu-world.com/forum/templates/CPUWorld/images/lang_english/icon_email.gif "[ Hidden ]"){kind=icon}
