Author: Christophe Theron
Date: 23:54:16 02/15/00
Go up one level in this thread
On February 16, 2000 at 02:47:16, Ricardo Gibert wrote:
>On February 16, 2000 at 02:12:21, Eugene Nalimov wrote:
>
>>On February 16, 2000 at 00:26:19, Christophe Theron wrote:
>>
>>>On February 15, 2000 at 22:45:28, Tom Kerrigan wrote:
>>>
>>>>On February 15, 2000 at 20:42:43, Ricardo Gibert wrote:
>>>>
>>>>>MIPS VR4121 is a 64 bit CPU according to NEC. Look at
>>>>>http://www.nec.com/Semiconductors/categories/679/981008.html
>>>>
>>>>You're right... Hmmm... I wonder what the "64 bit" measures. Maybe memory
>>>>interface? Because it seems pretty silly to have a full-blown 64-bit embedded
>>>>processor, when your desktop machine is still 32-bit...
>>>>
>>>>-Tom
>>>
>>>
>>>Wait a minute. The VR4121 processor claims pin-to-pin compatibility with the
>>>VR4111. And the VR4111 is a "false 64 bits" processor. Operations can be done on
>>>64 bits internally, but the data bus size is 16 or 32 bits. That is, there is a
>>>serious bottleneck between the processor and the memory when it comes to 64 bits
>>>values.
>>>
>>>I'm not even sure that this processor really supports clean 64 bits operations.
>>>All the docs I have mention 16 and 32 bits long instructions. How do you perform
>>>a move immediate with a 64 bits value if your instruction length is limited to
>>>32 bits?
>>
>>IBM/360, as well as IBM/370, also have no instruction "move immediate 32-bit
>>value"; if you want to load literal that is longer than 12 bits, you have to
>>load it from memory. Nevertheless it is true 32-bit processor.
>>
>>At that MIPS processor, loading/storing 64-bit values can be slower than 32-bit
>>values - but total impact on performance would be small enough. Small size of
>>cache is much more important, but I believe Crafty would perform as it's running
>>on P90-120.
>
>Windows 95 Pentium P5-120 159.4 Drystone MIPS
>
>Win CE VR4121 131mhz 174 Drystone MIPS
>
>So your prediction is not bad.
Do you have the Drystone MIPS for the DragonBall EZ? Motorola claims 2.7 for his
16.58MHz processor, but I wonder if it has been checked by somebody else.
Is there a web site with a compilation of Drystone MIPS for a bunch of popular
processors?
Christophe
>
>>
>>Eugene
>>
>>>And don't count on the 8Kb internal L1 data cache to store all the data needed
>>>by Crafty...
>>>
>>>A bitboard program looks like a poor choice for this architecture.
>>>
>>>
>>>
>>> Christophe
This page took 0 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.