Pentium D and Prime95

[georgekh]

ok guys so now since the new dual-cores are out, i'm thinking of getting one but i'm not exactly sure if its worth it, i mean can i run 1 test on the chip or should i run 2 test because its a dual-core, i dont know which one will be more faster and more benefitial. let me know what you think and if i get one i'll post benchmarks if its even possible.

[moo]

for prime 95 duel cores because they support 2 threads at once but i would susgest waiting till they perfect it more... right now from the benchmarks i saw from pcworld its getting a score about the same as a 3.6 ghz when the 2 duel cores are clocked at 3.2

[dsouza123]

Two copies of Prime95 would produce more work because even though Prime95
has two threads one is the calculation thread the other is the interface (screen)
and files thead.

I don't believe that a single instance of Prime95 can take advantage of two CPUs
for the calculation.
At least one of the other programs, (non x86), used to verify Mersenne primes does.

Without the affinity set Prime95 may bounce between CPUs, but not sure about
this.

[moo]

yes we need to consider that im not saying duel cores are bad but
A. there over priced give it a few months to simmer
B. yes 2 threads on real cores are better
C. pcworld is useing there software not mersenne software so were looking at i just discredited what i said in the above post
D. amd was totally disigned for duel core if you look they had everything in place long before intel.
E. intel rushed there duel cores well amds 64 bit procs were totally built to have a second core even there chipsets support it with a bios up.


all in all wait till amd releases there consumer version of the amd 64 bit proc.

[Joshua2]

http://www.axentmicro.com/huzrb/getd...547PG3000F.htm

http://www.axentmicro.com/huzrb/getd...47PG3000FT.htm

$15 difference for single core 64 bit cpu with 2 MB L2 cache and a 64 bit dual core with 2 MB L2 cache. Dual core will go twice as fast for p95 if you have two pn5's running. AMD's dual cores will be way more expensive than Intel's, although they will go significantly faster. However p95 favors P4 architecture, and their dual cores will be better values, at least at first. It may be awhile (1-2 years) before AMD brings down its prices.

[Joshua2]

http://www.anandtech.com/cpuchipsets/

These articles are very informative and are a must read if you are considering purchasing a dual core or not.

[dsouza123]

At this point AMD has dual core Opterons and Athlon 64 X2.
Intel has Pentium D and EE.

For the Athlon 64 X2
Clock, Rating, L2 Cache, FSB
----------------Athlon 64 X2 (Manchester Socket 939)
2200 4200+ 512KB 400
2400 4600+ 512KB 400
----------------Athlon 64 X2 (Toledo Socket 939)
2200 4400+ 1MB 400
2400 4800+ 1MB 400

For Pentium D and EE (smithfield)
ID, Clock, L2 Cache, FSB, Hyper Threading available
----------------Pentium D
820 2.8ghz 2MB 800 no
830 3.0ghz 2MB 800 no
840 3.2ghz 2MB 800 no
----------------Etreme edition
840 EE 3.2ghz 2MB 800/1066 yes

There are other EE (four more) but some are only 32 bit and all single core.

[dsouza123]

For dual core Opterons, AMD is focusing first on Opteron then Athlon 64
Intel is focusing on Pentium D/EE then later XEON.

ID, Clock, L2 Cache, FSB
Opteron 1xx
165 1800 1MB 400
170 2000 1MB 400
175 2200 1MB 400

Opteron 1xx
265 1800 1MB 400
270 2000 1MB 400
275 2200 1MB 400

Opteron 8xx
865 1800 1MB 400
870 2000 1MB 400
875 2200 1MB 400

[Mystwalker]

Originally Posted by Joshua2

http://www.axentmicro.com/huzrb/getd...547PG3000F.htm

http://www.axentmicro.com/huzrb/getd...47PG3000FT.htm

$15 difference for single core 64 bit cpu with 2 MB L2 cache and a 64 bit dual core with 2 MB L2 cache. Dual core will go twice as fast for p95 if you have two pn5's running. AMD's dual cores will be way more expensive than Intel's, although they will go significantly faster. However p95 favors P4 architecture, and their dual cores will be better values, at least at first. It may be awhile (1-2 years) before AMD brings down its prices.

AFAI see it, those are both single-core CPUs, because both are said to be Pentium 4 (type 630), whereas the dual-core CPUs are Pentium D (type 8xx).

Seems like the dual-core CPUs are more or less double as expensive as the single-core CPUs right now.

[Peter Nelson]

Originally Posted by georgekh

ok guys so now since the new dual-cores are out, i'm thinking of getting one

Interesting. I CAN get hold of 6xx chips and have benchmarked p95 on these.

But even as an Intel reseller, we might be able to get hold of 840 EE shortly (they were initially limited to only 4 builders including Dell and Alienware), but do NOT expect to get hold of 820, 830, 840. In fact I heard rumour that these may not be available in reasonable quantities until around December! Even AMD were disappointed they could not obtain any 840 chips when they tried!

However 64 bits EMT64 is here to stay, many new chips will support it and around August we may see some price changes making 64 bit 6xx the same price as equivalent 5xx. Within the sequence 6xx, if you keep the rest of your system costs minimal, low models offer best price/performance ratio.

EE is expensive. 820 does not have all features of 830, 840. Therefore 830 offers best price/performance. Real dualcore beats hyperthreading. However non extreme 8xx does not have hyperthreading. If you have lots of money dualcore EE has benchmarked very well at other applications so I expect Prime95 would also do well. However note these chips are HOT!

Intel pricing appears to add feature (64 bit, dualcore) at very similar price point to the next speed grade down. Therefore if available, 8xx is not too much of a premium to pay in my opinion.

Intel seem to think of 8xx as consumer products and Xeon as server/performance products. Dualcore Xeons will not be available until next year. In the meantime and 840EE chip appears to have similar performance to a DUAL socket singlecore Xeon system (and lower cost). So at least in the short terms 840EE would appear to beat Xeon.

The other thing to note about Intel 8xx is that you WILL need a new motherboard using a dualcore capable chipset. At the moment I only know of 945, 955 and the Nforce4 chipset for Intel which support this. Several vendors have designed such boards eg Intel, Gigabyte etc

Considering any Intel desktop system LGA775 is the necessity since 478 will be phased out pretty soon on P4 and gradually on Celeron D. Even if installing a 775 CeleronD, Pentium5xx or 6xx, I would be thinking ahead.

Better features like faster SATA are on these new chipsets not the old ones. Going for the new chipset will also ensure future upgradability to dualcore later should you wish. So, for example it would be nice to get a 630 on 955 and swap out the 630 for an 830 later when it became available.

However, as yet these 945 and 955 based motherboards have not yet reached the distribution channel so you will find it very difficult to actually buy one. This will probably change in the next month or 2 months.

I also heard reports that on testing 840EE using DDR2 @667 did not really achieve advantage over DDR2@533.

AMD are rolling out dualcore from top down. ie Opteron has gone dualcore but they are quite expensive. AMD 64 X2 should launch in June. Price has not yet been announced but should be reasonable and targetted at desktop. Various reviews suggest AMD architecture may have some advantages over Intel.

Unlike Intel, AMD X2 dualcore can be retrofitted into a S939 motherboard with just a bios upgrade to support it. Note these only support DDR(1) memory. However, DDR2 should be about the same price as regular DDR by the end of June.

As regards performance in 64 bit mode some people report that some math instructions take longer on Intel 6xx than AMD64, taking maybe 10 cycles. See paper linked off www.swox.com/gmp in their benchmark section.

[Joshua2]

I think Mystalker was right about those both being single core. Sorry. However, read Anandtech's page on price of second core for AMD vs Intel. This was amazing.
http://www.anandtech.com/cpuchipsets...spx?i=2397&p=4
For the Intel 2.8, only $78 to get the second core? Which if your running two p95's should be just about twice as fast, that looks a lot better value to me than AMD's second core. I agree though that AMD's design is better though, and in a year or two after they lower prices it might be better value also.