As many people will know as per
this thread, AOpen now have official support for the Merom CPU's in many of their S479 boards. (Unofficial support has been around for a while in the form of a modded beta bios however)
After a CPU came up on the forums I decided to give it a shot. Wanted to see first hand what all the fuss surrounding core 2 was actually about. I've been running a Yonah T2600 ES in the AOpen for a month or so now (and a T2500 before that) which was rather nippy. At 3.6ghz (single stage cooled) it was faster than pretty much any non conroe system out and some of the lower clocked core 2's.
Grabbed a T7400 ES Merom, Step 4 CPU. Would have liked a Stepping 5 chip as these seem to clock a little better but there's not a huge difference. After grabbing a bios update from the AOpen website the Merom dropped in and booted without a hitch. Note here, decided on the 1.06 bios rather than the latest 1.08 as some people had noted a few issues with the newer bioses no boots, hangs etc. If you buy a a-YDA new you'll have to make sure it comes with the 1.06 or later bios to ensure the board boots with a Merom installed. Didnt test with the original bios so can't confirm whether the board will actually work with different bios versions - might go back and check this if required.
So, here are the system specs...
Merom T7400 Step 4
AOpen a-YDG with bios 1.06. Vcore, vDimm, tCore, vChipset, and "cpuVTT" mod (believe this to be similar to vMCH) mods.
2GB GSkill HZ w/ Micron D9 chips
OCZ 520 Powerstream
EVGA 7900GT (DD Maze4 cooled)
DD TDX and Gray modded Mach1 to cool the CPU
Anywho, enough chat more results! The chip ran fine with auto vcore (actuall 1.48v due to the Vcore mod in place) at 200 fsb, with ram on the 533 divider. Cranking the FSB up to 220 and things were still rosy. 230 ended up being the eventual celing, more vcore didnt help here. It's a CPU limit, the chips hit a certain FSB and its very hard to get them any further. Performance was decent at a little over 3ghz, compared rather well to the Yonah at 3.6ghz. Due to the low FSB and lack of decent dividers the ram was stuck down at under 400mhz. This really hurt performance, even with timings tightened up as far as they'd run.
Frankly performance under water was a bit crap. The FSB cap (as with Yonah's) really hurts performance. The CPU had to be kept under 40 deg to maintain any sort of stability at 230. Not really hard for the Merom as it doesnt kick out any heat, even with 1.48v up its ****...
Don't have any screenshots of the early runs due to their crapness
After water came some decent cooling thanks to Gray Mole. The chilly head mounted perfectly on the heat-spreadered Merom in a matter of minutes. Shortly after she was sat at ~ -35 -> -40 at idle (Can't be 100% sure of exact temps due to the tCore mod on the board which raises the temp)
Chilled the FSB cap on the CPU's is lessened a little and they scale further.
From the 230fsb cap under water the chip ran to 247 FSB under single stage giving a clockspeed of just over 3.2ghz on the 13* multi.
Performance here was much better. Partly due to the extra 200mhz or so, and also due to the increased memory speed which was now a little over 405mhz at the same 3,3,3,12 timings.
Don't have a full suite of compares - those can wait for tomorrow
but have some quick 3dmark and pi 1m shots (yes yes I'm a bench hoe - get over it....)
Merom
vs Yonah
Even with a 300 mhz advantage and considerably faster running memory the Yonah is trampled on by the Core 2. Quite impressive really!
Next up a little 3dmark 2001 -
01 compare - Merom
Same clockspeeds, heres a screenshot of Yonah's best efforts
Again, the slower Merom utterly tramples the higher clocked Yonah. The scores are much more GPU limited with the Merom that the Yonah, would be nice to run some SLI and compare things a little further.
These scores are nothing compared to a decent conroe though, a decent E6300 or E6400 can achieve similar on air and should clock much further than this chip will ever be able to. It's certainly not worth going the Merom route unless you get a cheap chip and already have a AOpen board. Aircooling should get you to around 2.8ghz on stock (ish) vcore as long as you've got enough FSB!
