ATI’s Crossfire: Best Overclocker on the Market?
by Wesley Fink on September 27, 2005 12:05 AM EST- Posted in
- CPUs
Overclocking: ATI Crossfire AMD Reference Board
We have rarely tested a board with such incredible stability in overclocking. It was not always easy to reach our desired overclock with all of the options available in BIOS, but once we reached the overclock, it was exceptionally stable. We did notice that the ATI responds best to gradual increases in overclocking - it does not like, for example, to be set to 245 clock frequency. It will reach higher overclocks if the Clock frequency is increased gradually instead of one fell swoop. ATI has even added a "Gradual OC option" in BIOS to accommodate that reality.
The ATI Crossfire AMD reached a new record with our standard 4000+ Clawhammer. The highest previous overclock at stock multiplier was 240, but the ATI chipset went on to a stable 245. This would be quite an accomplishment for any board, but it is remarkable for a Reference board. The 315 Maximum bus frequency is also a great performance, second only to the DFI nForce4, which reached 318. We suspect that more time and tweaking may even have allowed us to break this record.
ATI clearly set out to build an enthusiast board that manufacturers could copy down to the smallest detail. Our advice to most manufacturers would be to copy the Reference Design. Unless you are certain that you can extract even more performance from this chipset, it is best to copy this top-performing Reference board.
At settings of 2T, we could reach even higher to a frequency of 325. There is a lot of discussion on the web these days claiming that you can minimize the impact of the 2T setting with certain options on Revision E AMD processors. We did not verify this claim in our tests, but we can tell you that all the talked-about options for 2T performance modes are in the memory timings section. It is little touches like these that tell us that enthusiasts in ATI or outside the company have had a big hand in the design of the Crossfire AMD.
| Front Side Bus Overclocking Testbed | |
| Default Voltage | |
| Processor: | Athlon 64 4000+ (2.4GHz, 1MB Cache) |
| CPU Voltage: | 1.525V (default 1.50V) |
| Cooling: | Thermaltake Silent Boost K8 Heatsink/Fan |
| Power Supply: | OCZ Power Stream 520W |
| Memory: | OCZ PC3200 EL Platinum Rev. 2 (Samsung TCCD Memory Chips) |
| Hard Drive: | Seagate 120GB 7200RPM SATA 8MB Cache |
| Maximum OC: (Standard Ratio) |
245x12 (4x HT, 2.5-3-3-10) 2940MHz (+22.5%) |
| Maximum FSB: (Lower Ratio) |
315 x 9 (3x HT, 1T) (2835MHz, 2 DIMMs in DC mode) (+57.5% Bus Overclock) |
We have rarely tested a board with such incredible stability in overclocking. It was not always easy to reach our desired overclock with all of the options available in BIOS, but once we reached the overclock, it was exceptionally stable. We did notice that the ATI responds best to gradual increases in overclocking - it does not like, for example, to be set to 245 clock frequency. It will reach higher overclocks if the Clock frequency is increased gradually instead of one fell swoop. ATI has even added a "Gradual OC option" in BIOS to accommodate that reality.
The ATI Crossfire AMD reached a new record with our standard 4000+ Clawhammer. The highest previous overclock at stock multiplier was 240, but the ATI chipset went on to a stable 245. This would be quite an accomplishment for any board, but it is remarkable for a Reference board. The 315 Maximum bus frequency is also a great performance, second only to the DFI nForce4, which reached 318. We suspect that more time and tweaking may even have allowed us to break this record.
ATI clearly set out to build an enthusiast board that manufacturers could copy down to the smallest detail. Our advice to most manufacturers would be to copy the Reference Design. Unless you are certain that you can extract even more performance from this chipset, it is best to copy this top-performing Reference board.
At settings of 2T, we could reach even higher to a frequency of 325. There is a lot of discussion on the web these days claiming that you can minimize the impact of the 2T setting with certain options on Revision E AMD processors. We did not verify this claim in our tests, but we can tell you that all the talked-about options for 2T performance modes are in the memory timings section. It is little touches like these that tell us that enthusiasts in ATI or outside the company have had a big hand in the design of the Crossfire AMD.
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Starcraftfreak - Friday, September 30, 2005 - link
So you are saying, the Board supports the dividers for DDR500 also on a Revision C core? I can remember when you published an article explaining it's a new feature of Revision E. Please clarify.SLI - Wednesday, September 28, 2005 - link
Everything I have seen thus far on the ATI chipset points to the FSB dropping to DDR333 *IF* you populate all 4 DIMM slots (with DDR400 RAM) This was an issue at the CPU level with AMD Athalon on board memory controller (at first) but has been addressed with the newer steppings. VIA and Nvidia chipsets have support for DDR400 with all 4 slots populated. This is a very important aspect to me and it needs to be addressed.Wesley Fink - Wednesday, September 28, 2005 - link
It was addressed in tRAS and Memory Stress Tests in the review - p.5. We had no trouble with 4 dimms at DDR400, though we did have to drop to 2T with 4 dimms as we do on every other AMD chipset. This is more a function of the on-CPU memory controller.sxr7171 - Wednesday, September 28, 2005 - link
I don't get it. We switched to SATA to get worse performance? SATA performed worse than IDE in every single benchmark.Scarceas - Tuesday, September 27, 2005 - link
I'd like to know what happens when you try two 6800s in a crossfire motherboard...I'm also curious about what happens why you try crossfire graphics cards on an NF4 SLI motherboard...
Early on I heard rumors that the motherboard implementation would be similar between the two and that mixing motherboard/graphics manufacturers *might* be possible...
Now the hardware is showing up and no one has tried it?
vailr - Tuesday, September 27, 2005 - link
Check: page 11 "Ethernet Performance" has format errors:http://www.anandtech.com/cpuchipsets/showdoc.aspx?...">http://www.anandtech.com/cpuchipsets/showdoc.aspx?...
Copied & pasted:
It will almost always be <em>much</em> lower than what we have measured.<br /> <br /> </span> </div> <div class="adcontainer"></div> <table border="0" width="100%"> <tr> <td align="right" colspan="2"> <table border="0" cellpadding="0" cellspacing="0"> <tr> <td><strong><a href="showdoc.aspx?i=2542&p=12" class="smalllink">Audio
tanekaha - Wednesday, September 28, 2005 - link
Ethernet page has same problem as b4 hereI`m using firefox latest beta and the browser considers the page done after this line.
Ntttcpr - m 4,0,
I guess u use a template for these reviews I had exactly the same prob with ( and commented similarly ) with I think the asrock dual article.
I guess not many others are getting this prob but I`m glad 2 see some! else has a prob and not just me.
What browser are u using ?
Wesley have u tried 2 view the article with firefox beta ? or even firefox ?
Wesley Fink - Thursday, September 29, 2005 - link
Articles are created in a document engine by our Web Editor, from basic information layouts we send the Web Editor. The engine generates HTML code. We don't individually generate the code for articles. Any problems with viewing the pages should be emailed to our webmaster Jason.Clark@anandtech.comtanekaha - Thursday, September 29, 2005 - link
Thanks for the replies gentsI am not using any blockers or extentions .. apart from FF default pop up blocker.
I will mail jason with the facts (as I see them)
I`ll also send the info to the FF team
THX again
tanekaha
JarredWalton - Wednesday, September 28, 2005 - link
If you're using any extensions to block ads or other content, you might want to try disabling those. I've been using Firefox for over a year now, and I don't have any issues with the pages. (Some pages render improperly the first time and I need to hit refresh, but that's generally only on long pages, and it seems more of a FF bug than anything.)