G.Skill techs done any testing on AMD Bulldozer FX?

[damric]

FX-4100
MSI 890FXA-GD65 with latest BIOS to support BD
RipjawsX 2x4GB DDR3-2133 CL9 Kit (F3-17000 blue heatspreaders)

Supposedly the new FX CPU supports 1866 multiplier. Won't work, no matter what the voltage/timing. I can do 1800MHZ CL8 though, and rock solid stable.

The best OC settings I could do for 100% stability are:
HT Reference: 225
CPU: x20 (4500MHZ) 1.46v (and never gets above 40'C under full stress)
CPU-NB x11 (2475MHZ) 1.26v
HTLink x12 (2700MHZ)
RAM is using the x800 divider for total 1800MHZ, 1.65v.
Using XMP timings except tightened by 1 after I found my maximum frequency.

It could be my motherboard holding me back. New FX CPU was supposed to have better IMC, but all of my tests have shown worse bandwidth and latency compared to AM3 chips at equivalent memory speed. Also the CPU-NB just won't clock as high.

I don't mind raising voltages substantially on my CPU/mobo if you have any suggestions. My system has excellent cooling and fully loaded temperatures are quite cool. I'm ready to juice this rig

How much can I raise RAM voltage and still be under warranty? I wouldn't mind trying to push 1.75v though them.

Also, why does my kit have a green PCB? Your picture, as well as newegg's, and bjorn3d all show a black PCB just like on my Snipers.

Can I remove my heat spreader without voiding the warranty? I want to put a low profile, copper heat spreader to allow a better fit and more airflow under my Hyper212+.

I have owned many G.Skill RAM kits, and in my opinion, they are always binned very tight, always working at advertised speeds, but with little extra headroom.

Thanks for the stickers you sent me a few months ago.

[Catscratch]

I hope you tried those setting on stock HT link speed ? You are supposed to keep HT around 2000 you know. 2700 is even outside HT 3.0 spec (which is only for motherboards not CPUs)

Do you have a link for them ? All I can find is the quad channel RipjawsZ http://www.gskill.com/products.php?index=437 are these what you have ?

[Tradesman]

I'll see if GSkill can take a look at the thread, I've played with the 8150 and 8120 and haven't been impressed as far as DRAM.....Sent AMD a few email and the best I've gotten back is that the FXs will support UP TO 1866, and basically that is only up to 1 stick per channel, have seen/heard of many 8120 that even have trouble w/ that, so with a 4100, I just don't know. Appears alot of people were drawn in by the hype of the DullDozer, I bought the 8150 to try when first released and had some trouble trying to run 16GB of 1866 (and wasn't impressed w/ performance) so I sold it off quick

[damric]

Thanks for the replies.

@Catscratch,

2600MHZ (200x 13) is stock HT Link for Bulldozer FX Chips. I was concerned about this as well, but it seems not to mind the speed. And yes, I did tests at ~2000MHZ like an AM3 chip

The kit is this.

@Tman,

I agree. I bought this chip to expand my HWBot profile. Something to play around overclocking/benching/ect, it's what I do The only thing going for the FX-4100 that I have seen so far is that it OC's like mad, and does so without producing too much heat. Otherwise, my past AM3 quad cores have out performed at stock what this chip can do overclocked. Quite sad, but Phenom I also kinda was a step back, so let's hope that this architecture gets a performance boost like Phenom II did.

[Tradesman]

Agree, picked up the 8150 thinking I might expand my building end since I dropped AMD a few years back, no such luck, put it side by side with a 2500K and not even close. AMDs new game plan seems to be saying it will run UP TO (a phrase they seem to love, like UP TO 1866), 20% faster under WIN8, but I've had the 8 Beta for a few months now and didn't see it happen, a slight gain (more like 6-7%). With the 8150 at $20+ more than a 2500K, I'll stay bowed out, trying to figure how to get hold of the upcoming Pile Driver, but don't really have hopes for it.

[GSKILL TECH]

Try sticking to x10 for CPU-NB and HT Link, and just OC the HT Ref Clock.

This method should be easier for the FX CPU. It is not the same as the previous CPUs.

RAM Voltage can be higher, but only increase if necessary. i.e. scale up accordingly

You can remove the heat spreader, but be careful, and make sure to keep it (just in case). Technically, it does void your G.Skill warranty.

PCB color just depends on the batch.

Our memory has the best headroom, you just need to know how to "unlock" it.

Thank you
GSKILL TECH

FX-4100
MSI 890FXA-GD65 with latest BIOS to support BD
RipjawsX 2x4GB DDR3-2133 CL9 Kit (F3-17000 blue heatspreaders)

Supposedly the new FX CPU supports 1866 multiplier. Won't work, no matter what the voltage/timing. I can do 1800MHZ CL8 though, and rock solid stable.

The best OC settings I could do for 100% stability are:
HT Reference: 225
CPU: x20 (4500MHZ) 1.46v (and never gets above 40'C under full stress)
CPU-NB x11 (2475MHZ) 1.26v
HTLink x12 (2700MHZ)
RAM is using the x800 divider for total 1800MHZ, 1.65v.
Using XMP timings except tightened by 1 after I found my maximum frequency.

It could be my motherboard holding me back. New FX CPU was supposed to have better IMC, but all of my tests have shown worse bandwidth and latency compared to AM3 chips at equivalent memory speed. Also the CPU-NB just won't clock as high.

I don't mind raising voltages substantially on my CPU/mobo if you have any suggestions. My system has excellent cooling and fully loaded temperatures are quite cool. I'm ready to juice this rig

How much can I raise RAM voltage and still be under warranty? I wouldn't mind trying to push 1.75v though them.

Also, why does my kit have a green PCB? Your picture, as well as newegg's, and bjorn3d all show a black PCB just like on my Snipers.

Can I remove my heat spreader without voiding the warranty? I want to put a low profile, copper heat spreader to allow a better fit and more airflow under my Hyper212+.

I have owned many G.Skill RAM kits, and in my opinion, they are always binned very tight, always working at advertised speeds, but with little extra headroom.

Thanks for the stickers you sent me a few months ago.

[damric]

Hey fellas. I wanted to give you an update. Things are going pretty darn good with the FX-4100 now. It just loves voltage I had to put 1.45v on the CPU-NB to stabilize. I'm happy with my 2x4GB (Blue) ripjawsX PC3-17000 at 2000 CL8 1T.

Below is excerpt from my blog on TPU about this. Thanks again for all of the help.

Back from the Mardi Gras parades, time for an update on my FX-4100.

A few weeks ago MSI sent me a new BIOS to try. Even with the new BIOS, I still couldn't boot with my memory on the 1866 divider.

I tried a few things like putting my memory in the other two slots (it's still there), didn't make a difference.

I figured since it looked like I was stuck at 1800MHZ memory, maybe I could further tighten timings.

That worked out pretty well. With some extra DRAM voltage (1.75v), I was able to hit CL7 1T stable. It didn't seem to scale performance wise though so I set it back to CL8.

I twiddled around with the sub timings in AMD Overdrive to save reboot time. Things were looking pretty futile.

What I hadn't tried since the BIOS update was to raise HT reference in AMD Overdrive. I wasn't expecting much, as my motherboard pretty much would refuse to boot anything over about 230 or crash in AMD Overdrive. But apparently not today.

240, no problem.250, still not crashing.260, pushed it too far. Will it work in BIOS? YES.

Now my stable 24/7 overclock (in BIOS):

HT reference: 250

CPU Multiplier: x18 = 4500MHZ

CPUNB Multiplier: x12 = 3000MHZ

RAM: x8 divider = 2000MHZ 8-10-9-28 1T

HT Link: x10 = 2500MHZ

My new MaxMem score:



After finding AMD's FX Tuning Guide buried in the corporate website, I've been experimenting with higher CPU clocks. It takes much more voltage for small gains, but the chip responds to the voltage quite well regardless. I have flirted with stabilizing 5.0 GHZ, but it looks like it will take more than 1.65volts. At this point, stress level temperatures are about 65'C with my fans at full blast and a cool room temperature. The chip definitely looks like it has more to give with some improved cooling. If fab improves, sucessor chips like piledriver should be even easier to overclock.

What really amazes me is the performance scaling above 4.5GHZ. CPU benchmarks score quite linearly, and even memory performance improves with a higher CPU clock.

AOD benchmark at 4500MHZ vs 5000MHZ (multiplier changed to 20):


Maxmem score increased at 5GHZ also:


I must say I'm now impressed with performance of this chip (at the 24/7 OC). Tuning the memory to 2000MHZ seemed to help it a bit, as I gained a few more minimum FPS in games. Average and maximum FPS were also gained, but I don't care so much about that as I usually game with V-synch on anyway.

Here are shots of performance scaling with memory at 1333, 1800, and 2000. I ran the CPU intensive "Action Scene" benchmark in Far Cry 2 and this is the results of 5 loops each.

1333 CL8


1800 CL8


2000 CL8


I dare say that real world performance now equals or exceeds my old overclocked Phenom II 955 rig. I think I spent about $160 on that chip, but I can't remember as that was a couple years ago now. I paid $120 for this chip, but it came with some free thermal grease and a $20 gift card, so effectively $95. I reckon the price to performance ratio is good. The only thing is that the Phenom II Zosma can still be found at around the same price. When those dry up, this will be the best AMD tweaker's chip for around $100. The fact that it's now working properly on my 890FX board is gravy.

[GSKILL TECH]

That's a serious gaming rig right there. Good work!

Thank you
GSKILL TECH