Investigations into Athlon X2 Overclocking
by Jarred Walton on December 21, 2005 12:00 PM EST- Posted in
- CPUs
RAM Ratios
We mentioned before that additional RAM ratios would be helpful, and higher end motherboards like the DFI LanParty series often provide them. The Infinity board is limited to DDR400, DDR333, DDR300, DDR266, and DDR200 – at least with the current BIOS. In reality, these are not exact speeds but rather the maximum speed at which the RAM will run with the CPU at stock speed. RAM speed on AMD K8 systems is derived from the CPU speed. With our X2 3800+, “DDR400” results in a CPU/10 RAM divider. 2000/10 = 200 MHz. The 10X multiplier actually makes for very nice RAM speeds, as CPU/12 = 166.7 MHz, CPU/15 = 133.3 MHz, and CPU/20 = 100 MHz. The DDR300 setting is the only one that’s off, as 2000/14 = 143 MHz.
With other motherboards, you may get several additional memory ratios, including those above DDR-400. This provides additional options for reaching maximum performance. In the end, the memory ratios come down to one point. All things being equal (i.e. with identical timings), higher bandwidth will be faster. It may not be a lot faster, but it could be a difference of several percent.
Was that a third strike against the Infinity motherboard? Though we would still say it packs a lot into a $90 board, we would recommend that serious enthusiasts spend a bit more money. The LanParty Ultra-D from DFI is only $20 more, and it has quite a few advantages over the Infinity that will be appreciated by more ambitious overclockers. The Ultra-D is basically the same as the SLI-D, only without official SLI support. Motherboards based on ATI's latest chipset also show promise – check out our motherboard reviews for more details on specific motherboards.
We could have tried several different motherboards to see if we could achieve better results, but this isn’t a motherboard or RAM article, even though it has aspects of both types of reviews. This is merely intended as an aid in showing people what can be achieved using the options available with various RAM types on one motherboard with one CPU. In other words, don’t read too much into the memory results. Use them as a guideline for optimizing your own system performance.
We mentioned before that additional RAM ratios would be helpful, and higher end motherboards like the DFI LanParty series often provide them. The Infinity board is limited to DDR400, DDR333, DDR300, DDR266, and DDR200 – at least with the current BIOS. In reality, these are not exact speeds but rather the maximum speed at which the RAM will run with the CPU at stock speed. RAM speed on AMD K8 systems is derived from the CPU speed. With our X2 3800+, “DDR400” results in a CPU/10 RAM divider. 2000/10 = 200 MHz. The 10X multiplier actually makes for very nice RAM speeds, as CPU/12 = 166.7 MHz, CPU/15 = 133.3 MHz, and CPU/20 = 100 MHz. The DDR300 setting is the only one that’s off, as 2000/14 = 143 MHz.
With other motherboards, you may get several additional memory ratios, including those above DDR-400. This provides additional options for reaching maximum performance. In the end, the memory ratios come down to one point. All things being equal (i.e. with identical timings), higher bandwidth will be faster. It may not be a lot faster, but it could be a difference of several percent.
Was that a third strike against the Infinity motherboard? Though we would still say it packs a lot into a $90 board, we would recommend that serious enthusiasts spend a bit more money. The LanParty Ultra-D from DFI is only $20 more, and it has quite a few advantages over the Infinity that will be appreciated by more ambitious overclockers. The Ultra-D is basically the same as the SLI-D, only without official SLI support. Motherboards based on ATI's latest chipset also show promise – check out our motherboard reviews for more details on specific motherboards.
We could have tried several different motherboards to see if we could achieve better results, but this isn’t a motherboard or RAM article, even though it has aspects of both types of reviews. This is merely intended as an aid in showing people what can be achieved using the options available with various RAM types on one motherboard with one CPU. In other words, don’t read too much into the memory results. Use them as a guideline for optimizing your own system performance.
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JarredWalton - Wednesday, December 21, 2005 - link
This may seem like a stupid question, but you did copy the SuperPi executable into two separate folders, right? Otherwise, the two running processes overwrite each others' data and one will always fail. Anyway, I don't find SuperPi to be a very useful stress test compared to Folding@Home, Prime95, and several other utilities; it just doesn't stress the system out that much IMO.Yianaki - Wednesday, December 21, 2005 - link
Yes of course it is in two folders. I realized that the SECOND time I did it Heh.Leper Messiah - Wednesday, December 21, 2005 - link
Thats actually a good thing, my X2 3800 does 2.65 at 1.425 vcore stable a rock. Looks like this x2 test is a good average indicator instead of most reviews which have the nice cherry picked silicon.JustAnAverageGuy - Wednesday, December 21, 2005 - link
Yeah, My Opteron 165 seems to top off at around 2.6GHz with the stock cooler.Araemo - Wednesday, December 21, 2005 - link
If you buy a socket 939 opteron, will it work in a normal NF4/etc mobo?A dual core opteron is tempting if it will work in the standard enthusiast motherboards. Get a nice heatsink and get it nice and toasty, I could turn my heater back off. :) And I hope 2GB RAM sticks go down in price within the next 9 months.. I'm still debating between a sweet laptop or a good overclocker desktop for my next computer, the desktop would be much cheaper, for sure, but it is a pain to take to LAN parties.
JustAnAverageGuy - Wednesday, December 21, 2005 - link
Most NF4 motherboards support the S939 Opteron, yes. Check the manufacturer's site to confirm though.Googer - Wednesday, December 21, 2005 - link
I found it a bit humourous that this http://images.anandtech.com/reviews/cpu/amd/athlon...">graphresembles a tent. It reminded me of the days in high school when kids would get fill in the bubble tests and use the answer sheets to do connect the dot drawings.
I wonder if Jarred had too much time on his hands?
kleinwl - Wednesday, December 21, 2005 - link
If you are going to start testing various cooling systems and how they affect max overclock... go ahead and throw in a Seasonic PSU as well. The Seasonic should be rejecting less heat into the case which may make as much difference in overclock as a more efficent Heat Sink. In any case... try it out please!<Note I have a XP-90, with a Antec SmartPower 2.0, on a venice... and I'm curious how such a case temp difference could affect the overclocking potential>
BigLan - Wednesday, December 21, 2005 - link
quote: Looking at the different RAM options, it's difficult to make a good case for spending tons of money on memory.I've always thought that spending a lot of extra cash on memory was a bad idea. It pretty much shows no improvement in Fear. It's nice to see a review of the everyday stuff.
Puddleglum - Wednesday, December 21, 2005 - link
The results for Fear looked bizarre. After reading some of the charts where 4xAA is used on games like Battlefield2 and FEAR, which would be a nice feature to show off on a high-end system, the numbers reveal marginal performance.I confess, I'm still using a Ti4200, which is only performing well in games because it's not drawing the DX9 stuff, and I've truly been waiting for an ideal video card to come out that's worth purchasing; but the new cards that are out right now are making it easy to sit back and wait for the hardware/software ratio to become a little more price-competitive.
Also, why is the OCZ PC4800 freaking out with BF2 when the CPU is overclocked to 2.1GHz?