Author: Ricardo Gibert
Date: 00:16:04 02/16/00
Go up one level in this thread
On February 16, 2000 at 02:54:16, Christophe Theron wrote: >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 I went to the following site for the Pentium statistic: http://performance.netlib.org/performance/html/dhrystone.data.col0.html This site does not seem to include statistics for HPC/PPC type CPUs. The VR141 statistic came from the NEC site. Given manufacturers penchant for exagerated claims, it must be taken with a grain of salt. Therefore, "rough" equivalence with the P5-120 seems reasonable.
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