Athlon 64 Revision E: Unofficial DDR500 Support
by Anand Lal Shimpi on July 11, 2005 12:05 AM EST- Posted in
- CPUs
High Speed Dual Core + New Memory Dividers
We’ll start off with the Athlon 64 X2 4800+.Featuring a 2.4GHz core clock, the 4800+ doesn’t necessarily meet our high clock speed requirement for needing a faster memory bus. Each core also features a 1MB L2 cache, which reduces its dependency on a higher speed memory bus. However, we are dealing with a dual core CPU here - which means that situations where both cores are being used are more likely to increase the chip’s memory bandwidth needs. Because of this, we’ll focus on improvements in multithreaded or multitasking environments, as well as looking at single threaded performance to measure the impact of the faster memory clocks.
According to our table of supported DDR frequencies by the DFI board, the 2.4GHz 4800+ gives us two options above DDR400 - mainly, 218MHz and 240MHz, or an unofficial DDR436 and DDR480, respectively.
Theoretical Memory Bandwidth Comparison
Just to make sure that these new dividers were actually doing something, we used the final 32-bit version of ScienceMark 2.0 to confirm that there were tangible increases in memory bandwidth:| Memory Speed | ScienceMark 2.0 Memory Bandwidth (MB/s) | % Improvement over DDR400 |
| DDR400 | 5378.08 | N/A |
| DDR436 | 5495.33 | 2% |
| DDR480 | 5851.52 | 9% |
With DDR436 offering only a 2% increase in peak theoretical memory bandwidth over DDR400, our only hopes for a performance increase are with the much higher bandwidth settings - i.e. DDR480.
Multimedia Content Creation Winstone 2004
Business applications barely made any use of the dual channel memory bus of Socket-939 CPUs, so we had no expectations to see any sort of performance boost from these new DDR speeds in tests like Business Winstone. Thus, we turn to Multimedia Content Creation Winstone 2004, whose Lightwave test is multithreaded and does take advantage of the X2’s dual core setup:| Memory Speed | MMCC Winstone 2004 | % Improvement over DDR400 |
| DDR400 | 41.9 | N/A |
| DDR436 | 42.3 | 1% |
| DDR480 | 42.7 | 2% |
The biggest performance difference that we see here is 2%, which is less than the 3% variation that we can see between test runs in this particular benchmark.
3D Rendering
3D rendering is another area where we see good use of dual core processors, but these tests also showed us a 0 - 1% increase in performance when comparing DDR480 to DDR400:| Memory Speed | 3dsmax 6 - SPECapc Rendering Composite | % Improvement over DDR400 |
| DDR400 | 2.78 | N/A |
| DDR436 | 2.8 | 1% |
| DDR480 | 2.8 | 1% |
| Memory Speed | Cinebench 2003 | % Improvement over DDR400 |
| DDR400 | 636 | N/A |
| DDR436 | 639 | 0% |
| DDR480 | 641 | 1% |
Even SPECviewperf 8 barely showed any performance increase (from 0 - 2%), and that suite of applications tends to be quite dependent on memory performance.
Video Encoding
DivX and Windows Media encoding tests have always been very memory bandwidth sensitive. Let’s take a look at the impact of the new memory dividers there:| Memory Speed | DivX 6 + AutoGK | % Improvement over DDR400 |
| DDR400 | 50.6 | N/A |
| DDR436 | 51.3 | 1% |
| DDR480 | 53.2 | 5% |
With a 5% improvement in performance, DivX 6 gives us the first indication of any truly tangible performance increases due to the higher DDR speeds unofficially supported by the new chips.
| Memory Speed | Windows Media Encoder 9 (fps) | % Improvement over DDR400 |
| DDR400 | 4.22 | N/A |
| DDR436 | 4.24 | 0% |
| DDR480 | 4.28 | 1% |
The same success isn’t seen in our WME test, with a 0 and 1% increase in performance at DDR436 and DDR480, respectively.
Gaming
Doom 3 is also a very good measure of the impact of memory bandwidth, as are most other 3D games:| Memory Speed | Doom 3 (1024 x 768 fps) | % Improvement over DDR400 |
| DDR400 | 121.9 | N/A |
| DDR436 | 124.3 | 2% |
| DDR480 | 127.2 | 4% |
Finally we see another situation where there’s a positive impact in memory performance. Here, DDR480 gives the X2 a 4% increase in frame rate at 1024 x 768. However, cranking the resolution up to 1600 x 1200 cuts that improvement down to 1%. The usefulness of the 10x7 numbers is in simulating situations where you are less GPU bound.
Overall, we’d say that there’s not that big of an improvement from using DDR480 with the Athlon 64 X2 4800+. The biggest performance boosts will occur in video encoding and games where you are not GPU bound, and even then, you should expect an increase in the 3% - 5% range.
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ElJefe - Monday, July 11, 2005 - link
Well, I could say this would have been a great test if only one thing: to show the effect of TIMINGS on this. I know the OCZ had sickest tight timings, but im talking about the difference of say, using 4 single gig memeory modules and then messing around with the timings, showing which is best. I know at 1 gig, most of those l33t ram flashy types of dual channel matches drop off and kinda go into hum-drum land.If i had an X2 system it would have 2 gigs on two chips or 4 gigs on 4 chips. I couldnt see a dual proc system built for simply faster gaming, it's meant to be a cookie monster of processes.
KristopherKubicki - Monday, July 11, 2005 - link
bupkus: DDR2 comes with the M2 socket next year. At least, thats according to the roadmap.Kristopher
fishbits - Monday, July 11, 2005 - link
"The ceil() function is a pretty basic mathematical function that returns the smallest integer value greater than its argument..."Think that should be "greater than or equal to." ceil(10.0)=10. Not that it exactly matters much in this context. Anyhoo...
I'm glad AMD is further ahead of supporting mem speeds than needed, as opposed to playing catch-up. Additional options and capability for their future items will pay off down the road if not now.
brownba - Monday, July 11, 2005 - link
#1"keeps getting better and better."
huh? did you look at the benchmarks?
what is better?
Anand just showed us to save our money, we don't the very fastest ram, so I guess that is better.
Wesley Fink - Monday, July 11, 2005 - link
#2 - The OCZ PC3500 GX is specially binned BH5. Anand had planned to use VX memory but it was out of stock as this article was being developed. OCZ binned some BH5 at 3.3V for 2-2-2 operation at DDR500 to meet the requirements of this review and turned it around in a few hours. The point is that OCZ PC3500 GX will NOT all operate at 2-2-2 at DDR500. The OCZ VX and Mushkin Redline, on the other hand, are both rated 2-2-2 at DDR500 at 3.5V. The VX/Redline are based on Winbond CH5 blanks.Wesley Fink - Monday, July 11, 2005 - link
#20 - There is a new official DFI BIOS in the works that is to post soon. However, as I mentioned in the nF4 Ultra roundup there are over 60 BIOS revisions avaialble for the DFI nF4 boards. Oskar Wu of DFI has posted many of the BIOS' at www.dfistreet.com, the DFI Forum website, or in the Forums at www.xtremesystems.org.yacoub - Monday, July 11, 2005 - link
[In keeping with our recently growing practice,] "We chose three CPUs to investigate the impacts of these new memory dividers: [The three you are least likely to own]: the Athlon 64 X2 4800+ (2.4GHz/1MB L2), the Athlon 64 X2 4200+ (2.2GHz/512KB L2) and the Athlon 64 FX-57 (2.8GHz/1MB L2)."hehehe
ksherman - Monday, July 11, 2005 - link
I know this is going to sound like a dumb question, so here it is. Where did you get the BIOS update for the DFI board? I have that board, and their website only lists an update throung March, nothing as recent as July...Stinger22 - Monday, July 11, 2005 - link
One small correction..There is also an Athlon 64 3000+ that is a Socket 939 and is Revision E.
Hacp - Monday, July 11, 2005 - link
#13, I know of one other mobo that supports 3.3 volts and many other ram sticks can get 2-2-2-5 at ddr500.