SOLVED Scrypt/Jane, Ram, Ram, and You.

[KonaKona]

You got thirtybird's interest (yacminer's developer), sent him your way...he didn't know the 7850 4gb heh

He might post here eventually...would be cool.

Uh oh.

 

[KonaKona]

I double post waaaay too much in this thread.

Turns out the 240 doesn't actually care much about TC, only gains .05khash or something between ~1gb ram use and ~4gb ram use.

Anyway it's cranking out ~3khash on my mining rig and I am DONE messing with it. I'll be revisiting this problem when the other 240s show up but I imagine they'll run fine at the same settings.

I'm also going to assume from this point forward that something is up with that rig that won't let it load high TC. Others feel free to try loading a 4gb card with 4gb of ram and see how it does... I'm really fed up of messing with all of this for now.

EDIT: Just kidding, the 240 is spitting out HW errors. I'm pretty sure this is a system (see: MB) issue here.

 

[ivanlabrie]

You need to allocate as closer to 4gb as possible whilst still using dedicated vram (check using gpuz/hwinfo).

I tried your lower TC settings and I get hw but my cards are crappy...The yacminer dev got them to do 2.8kh/s btw...and I'm pretty sure he didn't oc past the CCC limits.

 

[KonaKona]

If he got 2.8 on stock clocks or at 1015 core then he's either got magic cards or something to tweak that I don't. I did a pretty decent amount of testing today...

Unified YACoin tweaking theory

7850

When you increase rI, hash rates will increase along with it. After a certian point, the hash rate will increase more than it did before but it will be accompanied by HW errors. There is a very small range (10-20) between no HW errors at all and nothing but HW errors, and it's very easy to find a good tune. 

240

hash rates seem to increase to a point and then drop off, but then increase again afterwords. Interestingly, not only can much higher rI be run than on the 7850 but there were also 0 HW errors, regardless of the rI. 

-- Rates seem to center around multiples of 1280 --

1180/900 (not quite stable, probably 5-15mhz too high. Had troubles getting mem clocks to stick at high core speeds due to the software being used but it doesn't seem to make much of a difference anyway.)
-g 1 -ga 3
rI -- hash


1200 -- 2.328
1250 -- 2.423
1260 -- 2.441
1270 -- 2.461
1275 --2.470
1279 -- 2.477
1280 -- 2.478
1281 -- 1.457
1282 -- 1.376
1290 -- 1.29
1300 -- 1.3
1400 -- 1.376
1600 -- 1.568
1800 -- 1.756
2000 -- 1.945
2100 -- 2.04
2200 -- 2.137
2250
2300 -- 2.233
2350
2400 -- 2.328
2450
2500 -- 2.423
2550 -- 2.47
2600 -- 1.7
2650 -- 1.73
2700 -- 1.76
2750 --
2800 -- 1.82
2850 --
2900 -- 1.9
2950 --
3000 -- 1.95
3100 -- 2.0
3200 -- 2.07
3300 -- 2.14
3400 -- 2.2
3500 -- 2.27
3600 -- 2.33
3700 -- 2.395
3800 -- 2.46
3810 -- 2.465
3820 -- 2.47
3830 -- 2.478
3838 -- 2.481
3840 -- 2.483
3841 -- 2.01
3842 -- 1.959
3844 -- 1.92
3850 -- 1.90
3900 -- 1.91

Gaps 1 and 3 were consistently .5khash lower than their gap 2 counterparts. gap 4 was another .5 lower. rI of up to 10240 could be used at all gap levels but hash rates were the same as all other multiples of 1280.

I think I tried half and quarter TC values and got slightly lower (bit less than .1khash if memory serves) hash rates but IIRC, rI (including the silly high ones) would still stick. All testing was done with 3.4.1-yac2 on YACcoin (N=14).

Oh, and I couldn't break 3khash no matter what I tried. 2.9something was as much as that card was gonna push, but it was close enough to call 3kash. I think the most I could get at 1015 core was 2.6 or so.

 

[KonaKona]

Yeah another double post. Decided to take a stick out of my main rig to test at 4gb, had some interesting results.

I could only load the same amount as I could on my mining rig. This was regardless of how much ram was being used. The total came out to around 1791MB, or a TC of 28668 at lookup gap 2. I only tested this for YACoin (as I forgot to try scrypt before I shut the rig down and also since that's all that really pertains to me. These two systems had different amounts of virtual memory and free memory available (and I tried sucking down some ram on my rig as well, it made no difference), but still had the exact same TC limit. This is important for anyone building a new mining rig. 8gb of ram should be enough to feed all of your cards, maybe even 6gb.

I have to wait for some more cards to show up, but I would guess that the ram amount only pertains to how big of a TC you can load on each card, not how much TC you can use total between multiple cards. I've been wrong before however.

More testing to come later on.

 

[ivanlabrie]

I think that's the case, max amount of TC per cards needs X amount of ram, that's about it.

 

[KonaKona]

Just did another round of tests on my 240, here's an excerpt from the TC part:

--1150/1100 rI 1280--
TC (Thread ram MB/"Dedicated" ram MB) [RawInensity] Accepted:HW error
60480 (T3780 D????) ~3.019k NO HW (all [s]above tests[/s] a bunch of tests done with this setting, no HW)
45630 (T2835 D2878) ~3.013k NO HW (>40:0)
30240 (T1890 D1931) ~3.006k 12:4 (15:4)
28668 (T~1791 D1833) ~3.006k A<HW
^ w/ rI 928 ~2.215k 15:0
^ w/ rI 940 ~2.242k 12:0
^ w/ rI 950 ~2.266k 22:2
15120 (T945 D984) ~2.139k rI 900 A<HW
^ w/ rI 800 ~1.907k A<HW
^ w/ rI 700 ~1.67k A<HW

1gb ain't worth it. 

TC 30240 rI 940 1325/900 ~2.477k 12:1

While TC makes a minor difference in hash rates, it's main importance (as always) is to keep things running without errors. I'll also add that while with a higher TC the limit seems to be with memory speed or bandwidth, with lower TC core speed makes a bigger difference.

More info in another thread.

 

[KonaKona]

Anyone else seeing their UTC hashrate drop?
I got my 270x up to 200 Kh, and now it down to 140

I know the N-factor will change on the 28th, reducing our hashrates again, but it's the 26th....

http://www.overclockers.com/forums/showthread.php?t=743347 or http://www.overclockers.com/forums/showthread.php?t=741998 please.

 

[Silver_Pharaoh]

http://www.overclockers.com/forums/showthread.php?t=743347 or http://www.overclockers.com/forums/showthread.php?t=741998 please.

I saw "scrypt-jane" in the title and thought it was the ultracoin thread. My bad.

I'll get rid of that for you. (Fixed btw, clocks were stuck)

 

[KonaKona]

240s finally got in last night, had no issues loading the same TC for 3 cards in one yacminer instance (with one bat). More ram will be in this afternoon so I can try 6gb and 8gb.

Methinks this might be sticky/important thread sticky material now that I've got all the research done. I'll probably go back and rewrite the OP again...

 

[ivanlabrie]

cool!

I reinstalled my 4 240s, solid at 2.35kh/s with the stock bios. I was busy testing other cards but this week I'll try modding the bios for over volting.

 

[KonaKona]

cool!

I reinstalled my 4 240s, solid at 2.35kh/s with the stock bios. I was busy testing other cards but this week I'll try modding the bios for over volting.

If you overvolt, invest in a decent CFM fan (>100) to stick on the cards. I was having temp issues so I stuck an old 80mm screamer from a TT volcano sitting on the MB with air blowing across the cards and got a 30-40c(!!) temp drop on my hot cards.

 

[ivanlabrie]

I used a 140mm fan at 1300rpm...wasn't enough.

Should have used my 220cfm nidecs but no was too lazy.
I think I killed one of the cards at 1200mhz core. dammit

 

[ivanlabrie]

Fun fact:

280X's can do 4kh/s at stock, when a GTX 680 does 5kh/s mining N 14 chacha coins... :/

Some other figures: GTX 780 @ 1175mhz core 7.5kh/s, GTX 750 ti 2GB @ 1400mhz core - 3.6kh/s