Affordable Dual Core from AMD: Athlon 64 X2 3800+
by Anand Lal Shimpi on August 1, 2005 9:36 AM EST- Posted in
- CPUs
Power Comparison: Manchester vs. Toledo
In our first review of the Athlon 64 X2, we were astounded by the fact that the fastest Athlon 64 X2, thanks to its cool running 90nm process, consumed less power than any single core Pentium 4 processor, not to mention all of the dual core models.We also noted that a dual core Athlon 64 X2 processor used less power than a single core 130nm Athlon 64, once again a testament to AMD's transition to 90nm.
This time around, we're interested in the power consumption benefits of the new Manchester core. AMD says the core drops the maximum power consumption from 110W down to 89W, but what is that in the real world?
In order to find out, we performed one simple test; we clocked an Athlon 64 X2 4200+ based on the old Toledo core at 2.0GHz, the same clock speed as the X2 3800+, and measured the total power consumption of the system. We then swapped out the Toledo based X2 for a new Manchester based X2 to see, clock for clock, what the tangible decrease in power consumption was.
Remember, we're only looking at total system power consumption - obviously CPU power consumption will be a lot lower, but with identical system specifications, the CPU's impact on power consumption should be the major variable that we're measuring here.
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broberts - Wednesday, August 3, 2005 - link
ISTM that the choice of Intel mobo is mistated. Further, IMO using an ASUS high-end mobo as one test platform and any Intel mobo as the other gives the former at least a 3% - 5% performance advantage. I wonder too, were all of the ASUS mobo's oc features turned off?"The Test
Our hardware configurations are similar to what we've used in previous comparisons. For this test, we focused on CPUs at or around the Athlon 64 X2 3800+'s $354 price point.
AMD Athlon 64 Configuration
Socket-939 Athlon 64 CPUs
2 x 512MB OCZ PC3200 EL Dual Channel DIMMs 2-2-2-7
ASUS A8N-SLI Deluxe
ATI Radeon X850 XT PCI Express
Intel Pentium 4 Configuration
LGA-775 Intel Pentium 4 and Pentium D CPUs
2 x 512MB Crucial DDR-II 533 Dual Channel DIMMs 3-3-3-12
Intel 925XE Motherboard [<======= Really???]
ATI Radeon X850 XT PCI Express"
robh3 - Tuesday, August 2, 2005 - link
Rendering in 3dstudio max benefits from dualcore cpus. It however, also benefits from hyperthreading if this is a mental ray render. I'd like to see results for the pentium-d and amd-x2 when rendering in 3dstudio 7 with mental ray. I think the advantage is significant, especially in video renders as it's mathematically more effective to have more nodes rendering.For your future reference.
MetroRider - Wednesday, August 3, 2005 - link
very nice article indeed! know i just received three computers from Dell today with Pentium D processors, so i see the new X2 is a bit faster, but excited to try it out in general multi-tasking environments regardless.One question i haven't seen answered is: How does a dual-core cpu compare against a true SMP dual-cpu system? Example would be a Pentium D 840 (or AMD X2 4200+) vs. 2x Pentium 4 - 2.8 GHz Xeon system? For the price, dual-core seems great. How does it handle running Windows 2000 Server or 2003 Server or running as an Exchange server?
If anyone has any input or has tried this, I'd be interested in knowing.
thanks again (sorry if the request is too off-topic)
fitten - Thursday, August 4, 2005 - link
Oh... also, since AMDs cache coherency implementation and the way the dual cores work is more efficient than Intel's, so applications that have to pass ownership of cached data (L1/L2) back and forth a lot will be faster on AMD X2 machines. Of course, this type of application behavior is usually considered to be the result of poor design, so use well written apps :)masher - Thursday, August 4, 2005 - link
Actually, I'd give a slight (very slight) edge to Intel's approach on SMP systems....though AMD's Hypertransport is certainly far cleaner on paper, it hasn't paid off quite so well in practice. However, HT is considerably more suited for a NUMA-based multi-cpu architecture than for SMP. Unfortunately, there aren't many NUMA OS's out there at the moment...fitten - Thursday, August 4, 2005 - link
One question i haven't seen answered is: How does a dual-core cpu compare against a true SMP dual-cpu system?Depends. Dual CPU systems and dual core systems both have two cores running in them. The main difference is that two single core AMD machines (two Opterons) can have independent memory banks if you buy an appropriate motherboard. The dual core systems 9(both Intel's and AMD's) share the same pipe to memory. This isn't as big of an issue for AMD parts because the Athlon64 (single core) really doesn't make good use of dual channel memory anyway (dual channel over single channel is at best 20% faster in memory intensive apps while most see around 5%) so neither of the cores in the dual core setup get memory starved unless both cores are running full tilt (by benchmarks, I guess this would mean that if single channel were 1, dual channel were 2, the two cores running full tilt would need 2.4 channel memory to never be starved). The Intel parts, however, will suffer more. Dual channel memory on a P4 can be saturated by a single core so dual cores going all out can become starved a bit worse (one core would be 2, two cores would need 4/quad channel memory to never be starved).
So, your performance will depend on what types of applications you will be running.
Tujan - Tuesday, August 2, 2005 - link
Well Im missing the reasons for comparing the 640 Intel,and 630 D Intel when both are less than the AMD 3800+,and 3800+x2.True if you where to take the 'best of'in performance to price between both Intel,and Amd the 640 Pentium 3.2 would be the comparitor .
Performance alone though,true AMD 3800+ surpasses the P4 640 .The 3500+ AMD 64 would have been a closer comparitive if solely on a price basis.
With both the AMD 3500+,or the Intel 640 to be either choice in that price point to have. They compare in performance as well.Especially since the next Pentium pricepoint the 3.4 Ghz 650 is the closer comparitor.
The 3800+ AMD 939 single is still more expensive than the Dual-Core 830 D . With the newest AMD 3800+ still at the 400$ spot.
Comparing the Intel 640 to the 3800+AMD is lopsided.
The Intel 650 is the closer comparator,in terms of cost.Still though the Intel 640 remains the gulf between them when cost is the comparator.
Im missing reason author chose to compare these specific CPUs. Since the Intel is clearly not in same performance class.Although for even reach of benchmarks,would be the best'of''in price points to beat.Should have compared the Intel 650,to the AMD 3800+.
AMD 64 3500,AMD 64 3700 would have been closer comparitors to cost between the two,to match up performance.Seen the benchmarks before between them.AMD winning some,Intel winning some.Howebeit,the Intel has HT.etc.
AMD 64 3800+ CPU is a tough machine.AMD 64 3800 X2 twice as tough.
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Anybody know what the transistor count is for the Pentium D 830 ?
coldpower27 - Tuesday, August 2, 2005 - link
The Smithfiled is 230 million transistors, it's interesting though, AMD more then doubles transistors count going from Single core to Dual core, while Intel is the opposite.Tujan - Tuesday, August 2, 2005 - link
Thanks for reply. Can you give me the link/URL for a chart on the newer CPUs with transistor counts included. Or can you tell me for example,the website,to go to to look at the chart ?These new processors are simply nummy.
redhatlinux - Tuesday, August 2, 2005 - link
Once again, I believe Anand has shown un-biased data. I run a Dell hyperthreading rig, just because its convenient. BUT, as others have pointed, the X2's were designed from the ground up to be dual, on chip. To have to leave the core, and use the FSB, just shows that Intel is playing catch up. Benchmarks can, and often do show whatever the person running the benchmark wishes to show. Anand has ALWAYS, IMHO, tried to show, unbiased, accurate DATA. The basic design of the long piped Pentium will almost always favor Intel in benchmarks which, in essence are SIMD, in nature. That is, processing streams of data, with a single instuction. Price points, for ANY given CPU, GPU, HDD etc will always be Market Driven. The complexities, which go into the pricing decisions are well beyond the scope of this forum IMHO. AMD will continue to offer innovative design, over Intels 'brute force', more megahertz must be better, approach.