1GB DIMMs: FAST 2GB DDR Kits from Corsair, Gigaram, and OCZ
by Wesley Fink on October 11, 2005 2:55 PM EST- Posted in
- Memory
Impact of Athlon 64 Memory Controllers on 1GB DIMM Performance
While there has been a lot of talk about the different capabilities of the evolving Athlon 64 on-processor memory controllers, there really hasn't been much discussion of the limitations of some of the earlier Clawhammer controllers. We ran into this issue head-on in our first efforts at testing these 1GB DIMMs.
Most are aware that the early Clawhammer controllers did not officially support 4 DIMMs of any kind at other than a 2T Command Rate. In fact, this continued on in the current Rev. E controller. Some are also aware that the Clawhammer memory controller did not officially support DDR400 with 4 DS DIMMs - official support was DDR333. However, most board makers found that the controller really had no problem with 4DS DIMMs running at DDR400 and supported that "extended feature" in BIOS.
There are not the only differences in the memory controllers that come into play with the more demanding 1GB DIMMs. Our standard test bed CPU has been the 4000+, specifically the original Clawhammer version. Today, you can also buy a 90nm Rev. E version, but we had found no reason to upgrade from the Clawhammer version - until these 1GB tests. Our first efforts with the OCZ 2GB kit saw things very much out of the ordinary in our memory testing. First, Super Pi was no longer a reliable indicator of top speed. In the past, we could run Super Pi, and if it ran, we were confident that the rest of our memory test suite would run without problems.
Now, with the 1GB DIMMs and Clawhammer controller, Super Pi could run perfectly at a CPU clock some 15 points higher than what we could get Quake3, or Return to Wolfenstein to run. With 1GB DIMMs, gaming was now the most demanding task in our suite.
The other strange behavior with our Clawhammer was overclocking. Our first efforts with the OCZ 1GB DIMMs topped out at DDR520. That seemed OK until we saw others doing 540 and even higher on simple air cooling with the same memory. What was different? We finally realized that the highest overclockers with 1GB DIMMs were using processors with Rev. E memory controllers.
Once we switched to an FX57, with a set multiplier of 12X to produce comparable results to past memory reviews, our overclocking clock frequency went up to DDR550 - 30 points higher. The Super Pi issue remained, since we could run Super Pi and Sandra Memory tests all day at DDR565, but gaming tests crashed the system at any setting over DDR550.
It is clear that 1GB DIMMs put a much greater demand on system resources than 512MB DIMMs. It is also clear that the newer Athlon 64 memory controllers are better at meeting the demands of 1GB DIMMs in overclocking. We went back and compared performance of 512MB DIMMs on Clawhammer and Rev. E just for a sanity check. There was virtually no difference in 512MB overclocking on either memory controller - pointing again to the extra demands of 1GB memory modules.
Our advice is to use a recent processor and memory controller with 1GB DIMMs if you plan to overclock the memory. If this is not possible, then expect lower overclocks from your 1GB DIMMs.
While there has been a lot of talk about the different capabilities of the evolving Athlon 64 on-processor memory controllers, there really hasn't been much discussion of the limitations of some of the earlier Clawhammer controllers. We ran into this issue head-on in our first efforts at testing these 1GB DIMMs.
Most are aware that the early Clawhammer controllers did not officially support 4 DIMMs of any kind at other than a 2T Command Rate. In fact, this continued on in the current Rev. E controller. Some are also aware that the Clawhammer memory controller did not officially support DDR400 with 4 DS DIMMs - official support was DDR333. However, most board makers found that the controller really had no problem with 4DS DIMMs running at DDR400 and supported that "extended feature" in BIOS.
There are not the only differences in the memory controllers that come into play with the more demanding 1GB DIMMs. Our standard test bed CPU has been the 4000+, specifically the original Clawhammer version. Today, you can also buy a 90nm Rev. E version, but we had found no reason to upgrade from the Clawhammer version - until these 1GB tests. Our first efforts with the OCZ 2GB kit saw things very much out of the ordinary in our memory testing. First, Super Pi was no longer a reliable indicator of top speed. In the past, we could run Super Pi, and if it ran, we were confident that the rest of our memory test suite would run without problems.
Now, with the 1GB DIMMs and Clawhammer controller, Super Pi could run perfectly at a CPU clock some 15 points higher than what we could get Quake3, or Return to Wolfenstein to run. With 1GB DIMMs, gaming was now the most demanding task in our suite.
The other strange behavior with our Clawhammer was overclocking. Our first efforts with the OCZ 1GB DIMMs topped out at DDR520. That seemed OK until we saw others doing 540 and even higher on simple air cooling with the same memory. What was different? We finally realized that the highest overclockers with 1GB DIMMs were using processors with Rev. E memory controllers.
Once we switched to an FX57, with a set multiplier of 12X to produce comparable results to past memory reviews, our overclocking clock frequency went up to DDR550 - 30 points higher. The Super Pi issue remained, since we could run Super Pi and Sandra Memory tests all day at DDR565, but gaming tests crashed the system at any setting over DDR550.
It is clear that 1GB DIMMs put a much greater demand on system resources than 512MB DIMMs. It is also clear that the newer Athlon 64 memory controllers are better at meeting the demands of 1GB DIMMs in overclocking. We went back and compared performance of 512MB DIMMs on Clawhammer and Rev. E just for a sanity check. There was virtually no difference in 512MB overclocking on either memory controller - pointing again to the extra demands of 1GB memory modules.
Our advice is to use a recent processor and memory controller with 1GB DIMMs if you plan to overclock the memory. If this is not possible, then expect lower overclocks from your 1GB DIMMs.
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Wesley Fink - Tuesday, October 11, 2005 - link
The published "ram guy" link is the one printed on the Corsair retail package. We also tried the link and it connects to the Corsair Help Forums.If you have another link please list it in the Comments.
Madellga - Tuesday, October 11, 2005 - link
I am using this OCZ kit (EL, not the one in the review) since August on a San Diego / DFI combo. It goes to 230@2.5-3-2 with 2.7V and 1T.I tried also 4 sticks (a friend bought it also) and we made to 220@2.5-3-2 with 2.7V and 2T.
I didn't try above 230, as the OCZ Guy pointed the 230 to be the limit. I am using 180/200 or 166/200 to overclock the San Diego, leaving the memory between 220-230.
It is rock solid, it can Prime all night without mistakes.
I prefer to have more memory even if a bit slower - it is much worse to have Windows writting to the swap file.
ElFenix - Tuesday, October 11, 2005 - link
just to see how much the difference is when going from 1 gig to 2 gigsWesley Fink - Tuesday, October 11, 2005 - link
We tested many applications with 1GB vs. 2GB of ram. BF2 greatly benefited, but nothing else we've tested so far really improved much with 2GB. That will likely change with the release of newer, more demanding apps and games that take advantage of the new dual-core processors.One High-Performance memory company told us that after they saw what 2GB did for BF2 they ran 1 vs 2 on every game they could get their hands on. The goal was to publish benchmarks to show the advantage of buyers using 2GB instead of 1GB - and sell more memory. They privately told us they also found no real performance improvement in anything other than BF2.
We do expect 2GB/4GB will make a difference in multithreaded and true 64-bit apps in the future. Of course multi-tasking also normally benefits from more memory.
Johnmcl7 - Wednesday, October 12, 2005 - link
The only other game I've seen people recommending 2GB for is the FEAR demo but of course it's not final yet.Good read though, I thought the discussion on the A64 and the various ram issues was particiularly useful.
John
Margalus - Wednesday, October 12, 2005 - link
2Gb make a good difference in WoW also.Vesperan - Wednesday, October 12, 2005 - link
Wesley,the memory combinations on the 'Why 1GB Dimms?' page could be shown as a 2x2 matrix (with 2/4 dimms on one axis and 1T/2T on other). Performance at each combination could be shown - except of course for 4 dimms at 1T. Currently the article contrasts the 2 dimms and 1T combination with 4 dimms and 2T, could it be possible for you to add 2 dimms at 2T?
I would just like see the effect of 1T to 2T, or 2 dimms to 4 dimms ceterus paribus - that is, all else being equal. While I dont think the missing combination (2 dimms at 2T) will undermine your arguments made, I would like to see how it fits into the overall picture.
Phantronius - Tuesday, October 11, 2005 - link
I did, BF2 runs so much better as a resultPhantronius - Tuesday, October 11, 2005 - link
1st!!! Honestly, since i've given up overclocking, I threw in 2 1gig Platnium Corsair XMS modules in my new Athlon 64 setup and it works fine and stable, couldn't give a shit if my "timings" are as *looot* as they could be.DigitalFreak - Tuesday, October 11, 2005 - link
Well good for you