Mobile Barton 2500+ hits 2.5GHz easy, but Asus A7N8X Dlx R2.0 limits to 198 FSB stably?

[selfbuilt]

My old non-mobile Barton 2500+ (Week 8/03: AQUCA 0308TPEW) and Hynix PC400 2x512MB dual channel (SPD: 3-3-3-8 at 200MHz, HY5DU56822BT-D43) would never do above ~180 FSB stably on my Asus A7N8X Deluxe Rev 2.0 board, BIOS 1.07. This seemed likely to be the memory's fault, even though that particular DIMM set has been validated to run on the newer A7N8X-E and -X and -VM boards. However, I couldn't rule out the Barton, since some early week 7-8 were known to have problems >185 FSB.

Well, I took the plunge and upgraded to a mobile Barton 2500+ (Week 8/04: IQYHA 0408XPMW) and top-of-the-line, low latency, Corsair 2x512MB TWINX1024-3200LL (SPD: 2-3-2-6 at 200MHz, tested on the A7N8X platform). The old parts were passed along down the family

Overall, system runs great ... I can get 2.38 GHz stable at CPU 1.65V (set), and 2.48 Ghz at 1.675V (the Asus mobo overvolts about ~.5V). Peak temps under full load only 45-48C (depending on ambient) with Vantec Aeroflow with AS5 after several week "burn-in". Sandra give this a PR rating of almost 3600, which isn't bad at all!!!

My one small problem: I can't take it further since I'm unable to run Prime95 stable above 198 FSB.

At 198 or lower, I'm consistently Prime95 stable at least >5 hours, repeatedly (as long as I've tried it). But >198, I fail Prime95 usually within 1-2 minutes, and always within 1 hour for sure. It's defintely not the Barton, since I can run it stably at 200 FSB if I run the mem async at 166. And I get the same type of Prime95 errors if I run the mem at 200 and the Barton async at 166.

However, I suspect it's actually my Asus mobo that's to blame.

Although it is a Rev 2.0 board, it is one of the first (I bought it before we knew about the 2.0 boards, and was pleasantly surprised to discovered it was one afterwards). I've seen comments on various discussion boards that some of the early 2.0 boards are not Nvidia Ultra 400 chipsets (i.e. still have the original 400 chipset of the v1.06 boards), and have problems running at 200 FSB. It seems 198 is a magic number for certain other holders of these early boards as well.

Another reason I suspect it's the board and not the memory is that reducing mem timings (i.e. 7-3-3-2.5, 8-3-3-3, etc.) and raising DIMM voltage (e.g 2.8V) has absolutely no effect on Prime95 stability. Also, the difference is dramatic: 198 FSB, no errors at all, 200 FSB immediate errors. My old memory got increasingly worse >180, as you would expect ... this rapid shift >198 leads to me to suspect a chipset problem with my board. I welcome your thoughts, though.

Anyway, despite that little hiccup, I can live with 198x12.5 pretty easily . Here's my system specs and some benchies:

Mobile Barton 2500+ (IQYHA 0408XPMW) @ 192x12.5=2.48GHz, 1.675V (set, actual ~1.73V)
Corsair 2x512MB TWINX1024-3200LL @ 2-3-2-6, DIMM 2.7V
Asus A7N8X Deluxe Rev 2.0, BIOS 1.07
Vantec Aeroflow CPU cooler, Artic Silver 5
ATI RADEON 9500 PRO (stock), AGP 1.6V
WD 8M 80GB, SB Audigy 2, DVD-burner, etc, etc.
Windows XP Home SP1
Antex SX-1030 tower, with cooling fan on side panel
Antec 480W True Blue PSU (controlling 2/3 case fans)

---------------------

Scores are as follows (average of 2-3 readings):

"2500+" 166x11 (2-3-2-5) ..... "3200+" 198x11 (2-3-2-6) ..... "3500+" 198x12.5 (2-3-2-6)


PCMark CPU: 5693 ..... 6767 .... 7628
PCMark Mem: 5288 ..... 6145 .... 6427
PCMark HD: 868 ....... 869 ...... 867

Sandra04 CPU-A: 6929/2886 ......... 8212/3426 ......... 9360/3894
Sandra04 CPU-M: 17293/18472 .... 20524/21816 .... 23330/ 23914
Sandra04 Mem: 2555/2414 ......... 3036/2861 ......... 2968/2855
Sandra04 HD: 28MB/s ............... 28MB/s ............... 28MB/s

3DMark 2001SE: 12800 ...... 13650 ....... 14045

UT2K3 1024 (flyby/bot): 180.1/74.6 ..... 193.7/87.3 .... 199.4/94.1

UT2K4 1024HQ (min/avg/max): 27.4/79.6/101.6 ... 32.3/86.9/110.9 .... 35.8/94.2/119.5
(using custom UMark benchie)

------------------

So, an expected 30-35% boost in synthetic CPU scores, and 20-25% boost in real-world gaming FPS benchies. Not bad for virtually stock voltage!

Sorry for the long post, but you're looking at about 3 weeks of testing/tweaking on my part - needed to get it off my chest.

 

[BlindBartimaeus]

Nicely done...making me wonder if I should go for the mobile barton or go for the 3000 A64 and do some tweakin elsewhere

 

[DAPUNISHER]

Nice overclock It does sound like the board is the problem, if you can adjust the vdd chipset voltage through the bios or physically mod the board to increase it your fsb problem should be overcome. I've run old A2 chipsets@211fsb thanks to the vdd being adjustable to 1.8v in the bios on the Soltek nF2 boards so I'm certain if you have a A3 or A1/C1 chipset it'll be gravy with a slight boost. Of course not being familiar with the board I don't know if anyone has a mod or bios that allows vdd adjustment for it.

 

[selfbuilt]

Originally posted by: DAPUNISHERNice overclock It does sound like the board is the problem, if you can adjust the vdd chipset voltage through the bios or physically mod the board to increase it your fsb problem should be overcome.

Thanks, these mobile Bartons really are great o/cers. And I've had the same thought about upping the vdd (even wondered if a northbridge cooler might help?), but I don't know of any way of moding vdd on this board. Even the uber BIOS only unlocks higher vagp/vdimm, as far as I know (never tried it personally). And I guess I could replace the northbridge heatsink and take a look at the stepping to be sure, but I don't feel like completely disassembling my rig at the moment.

 

[AWhackWhiteBoy]

i keep repeating this all over the forum, its a known issue with the Asus boards. they really dislike the 200FSB, i'm not the only person who had the problem. i had to RMA the board for that and a few other reasons. not all the revisions and models of a7n8x have this problem, but some of them do.

this isn't to be mixed up with the 166 models though, some don't support 200 at all.

edit: just some extra info, i personally experienced the A7N8X-E Dexlue. couldn't pass 195.
i took the same ram and cpu and put it in a DFI lanparty and got 225 before my ddr400 came out unstable in prime95

 

[hytek369]

wow, nice OC. sell your asus for a dfi or abit

 

[selfbuilt]

Originally posted by: hytek369
wow, nice OC. sell your asus for a dfi or abit

Yeah, if I had known this last year, I would have gone for the Abit board. But for right now, I was just looking for something to tied me over until A64's systems mature a bit further (sockets, chipsets, mem, etc). I think just under 2.5Ghz will do for a few months

 

[JSSheridan]

Have you tried a different bios yet? That could be what you need to adjust. My v1.04 deluxe would run at 200fsb with the 1006 bios, but not with any other. Peace.

 

[jdogg707]

If all else fails you could probably buy a NF7-S 2.0 for what you could sell that Asus for and it would probably yield a much higher OC for you. I had very good success with my NF7-S and 2500+

 

[selfbuilt]

Originally posted by: JSSheridan
Have you tried a different bios yet? That could be what you need to adjust. My v1.04 deluxe would run at 200fsb with the 1006 bios, but not with any other. Peace.

I had heard that earlier BIOS versions were better to o/c on this board, so I suppose rolling it back might help. I'll give that a try when I get the time to play with it some more.

 

[SilentAssassin]

If I remeber right, bios 1004 is the best so try that one first.

 

[Zebo]

crank bus to ~220, set multi to 8 and Vcore to ~1.6 and if it works it's not your board but chip limiting you.. oh and to rule out mem set it to 3-3-3-X

 

[thescreaminglord]

hey guys, i'm new to the forums so thought i'd chip in my 2ence worth

i only had my a7n8x-e deluxe a few days and have managed to get my xp3000 running at 221 fsb..
annoying tho, the fsbram ratio is way out of sync...for sum reason this memory won't run at ddr400 on this board either in single or dual channel i have tried looser ram timing and raising the voltage.
i also can't get my pc to boot at 12x210, just says it failed cos of overclocking
wondering if anyof u guys had any experience or info on this

thanks guys...btw

PSU = Tagan 480W 28a/12v 48a/5v 28a/3.3v