ok i incresed my LDT voltage and my chip performs faster almost 3k in 3dmark01. and my FPS in games have gone up. just by upping the ldt voltage.
i'm at 312x9 on my venice 3000+
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ok i incresed my LDT voltage and my chip performs faster almost 3k in 3dmark01. and my FPS in games have gone up. just by upping the ldt voltage.
i'm at 312x9 on my venice 3000+
Really, nice.. :worship:
How much did you increase the voltage? And how much faster is it in benchmarks and FPS demos/gameplay? Might try this when I return home.
i maxed it out on my DFI board 1.5v
all it does is increase the chipset voltage....nothing else, maybe you had different settings and din't know it :)
Filter,
I think LDT Voltage is covered in this rather excellent OCing guide...
http://i4memory.com/showthread.php?t=327
...also covers a large number of other settings related to OCing so get reading :)
nope only ldt voltage. once i raise it my scores go up.
probbaly makes something more stable...
did you do it right after the computer booted back up??
I noticed the same thing. 2900 to 3200 in 3dmark05 if you can believe that.
edit: did some testing with a different CPU(venice 3200+). same results. LDT at 1.2 = 2913 in 3dmark05. LDT at 1.5 = 3250. Unbelievable.
no i was turning voltages down to reduce heat. to find out what voltages my system was stable at. well i notice for a while my 01 scores were down and my framerate was down in certain games. this bugged me for a while. well i went back in and turne voltage back up on ldt and bam my scores are back
I'm sure increasing the voltage to the chipset just made it more stable allowing for better performance. It works the same way when your overclocking your video card and the performance starts to drop when you've overclocked too far.
What on the chipset is being stressed, though? I'm at 840 HTT. Also, I didn't know that LDT was chipset voltage. So there are two voltages for one chip?
edit: I did two more runs at 1.5v and I was unable to duplicate the 3250 score or anything close to it. I'm using the EXACT same settings. Very odd.
it's variable, always defrag hard drive, fine tune ur ram timings trust me i had the same probs
so this whole turning up the ldt volts for higher scores issue is not concrete and guaranteed?
no, but it won't hurt anything to try it...
Quote:
Originally Posted by cantankerous
im not saying it will increase your score. i was wondering what it was because when i turned it down my scores went down when i turn it up my scores went up.
nice o/c in ur sig there filter ;)
yeah i'm at 312x9. and when my ldt voltage is set an min my scores go down when its set at max in bios my scores improve. what is the NB voltage
the voltage that goes to the nf4 chip ;)Quote:
Originally Posted by Filter
so in a nutshell a64 has 2 voltage set on cip vcore and ldt?
Yeah but your Vcore is made up of VID and an Percent Increase over VID... So then there are 3 voltage "types".Quote:
Originally Posted by Filter
well to break things down all the way, there's like 7 voltages.
1. the actual VID, which is the base core voltage
2. a % over VID, which is useful for pumping your core with voltage. not all boards list it as a % over VID, like the msi k8n neo's, but it still is.
3. Startup voltage. simple enough, the VID your computer boots with. handy for some debugging. i don't know of any boards that have this other than the dfi nf4
4. Vdimm. no need to explain
5. VTT. the voltage that the ram signals run at, usually 1/2 Vdimm
6. VDD. chipset voltage, usually for the northbridge, or in the nforce3/4's case, just the main chip :D
7. LDT voltage. the voltage of the HT link signal
8. AGP voltage. another thing that shouldn't need explaination :p:
there are of course others, such as the memory controller voltage (which i think is either VTT or Vcore, not sure) but very very very very few boards allow the adjustment of these ;)
(note: i'm not 100% sure about some of these. feel free to correct me if i'm wrong)
Some one reallly needs to test this properly first..for now im subscribed :D
just tested it again does same thing. can anyone else confirm this? or am i just seeing wierd crap. thinking about doing a reinstall and testing again.
i'm thinking it's just not "stable" without raising the voltage some, thus the added "stability" helps out performance :)
yea, I'll try later on tonight when i have time...Oh and when My PC decides to stop turning on and off
^^ hehe your DFi does that too! yeah nice trick... my damn comp shuts off when it's sleeping. Hitting power seems to awaken it as if it was just an advanced mode that makes the board seem off (no fans spinning, just that yellow standby light, but hitting power the desktop arises and fan noise returns), but at reduced clocks and MORE voltage (LDT, vcore, and nb voltage).
If i dont raise my LDT voltage by a tad my OC is not stable so yeah... voltage doesnt increase scores really, jyst might provide more STABLE MHz... even when BIOS is set the same then it's the stable part to harp on!
did anyone experiencing this speedincrease with voltage increase test if the lower voltage was prime/memtest/occt stable for a longer period?
if it is, then this really is strange
it it aint, it actually still is strange, since i thought only intel slowed certain things down when things got a lil hot / ?instable?
got me on this.
wow this is interesting.. voltage normally shouldn't have any influence on performance.. maybe stability but not performance.. very strange.
The only explanation i can come up with is that perhaps Hypertransport works with packets, and if it messes up sending one... maybe they are resent untill they DO get through correctly?
This way you wouldn't experience instability even if it is really there (say 10% of the packets arrive mangled or malformed), just the performance would be lower.
Filter, you're on a 312 HTT right, what's your LDT multiplier?
3x312=936MHz or 4x312=1248MHz ?
If it's 4x that would explain why the HT link has trouble sending data.
Try turning it down so you stay below 1000MHz, and then see if changing the LDT voltage still has any influence on your scores.
my thoughts exactly.Quote:
Originally Posted by Gogar
packet loss packet loss packet loss
When you have a phone modem you need to reduce the packet size for sending and recieving on the internet. Why? Because if it takes too long for the packet to be sent, it will time out and the server will start sending it to you again.
In this case, when a packet is sent it contains a parity bit. So for a 16 bit piece of data it will send an additional parity bit with it. The parity bit makes it so that there is an even number of 1's, that way if a single bit gets flipped (1 to 0 or vice versa) the reciever will know that the data was corrupted (there will be an uneven number of 1's).
Increasing the HTT (LDT) signal voltage will increase the slew rate of the signal. The slew rate is the rate that the voltage changes when you go from a 1 to a 0 or vice versa (think of the slope of the signal when you go from a 0 to a 1). When you increase the HTT freqency, the data lines may not have enough time to switch values, yeilding corrupted data.
I suspect that your HTT is tuned too high, and that you'll get a higher score by turning it down (keep it below 1000 like mentioned before). I'd turn down the voltage too to keep things cooler. As far as stability/preformance is concerned - maybe only the first bit is ever corrupted or some situation like that.
ok im gonna try this now i hope i can get a higher score lol ill try anything
________
YourMary
Only Oskar Wu could answer this theory, but maybe if the LDT multi is at auto and you set maximum LDT voltage it may auto select a higher LDT multi?
I'm at 3x htt multi
i experienced a better "performance" with the onboard nic with incresed ldt-voltage compared to default Before when i was downloading the computor would start to "lag" the cpu usage went up and down and it was near impossiple to move the mouse around and starting and closing windows etc took forever. No it dosen't and i can downlod. Strange since i only took a chance but hey it works. :toast:
What components will heat up with increasing LDT voltage?
Have you guys noticed any difference in the SuperPi benchmarks with a higher LDT voltage?
i did a superpi run once, with a tad lower vcore the score was 0.1sec better,
repeated this few times and got the same thing.
so pumping the procc with voltage ain't good for finetuning your rig:)
so this might be with 3dmark too ;)
LDT is the lightning data transport (http://www.hypertransport.org/docs/spec/ldt_spec1.01a_with_comment.pdf#search='LDT%20light ning%20data')
Using the LDT multiplier and the Bus speed the chips is at is how to calculate it. Using a program like CBID (central Brain Identifier) you can identify how high it is running. You want to keep the LDT to 1000 Mhz or below on the nforce4. Only when running more than 1000 MHZ LDT should you need to increase the voltage to it. I just helped someone last night with a 146 Opteron break 2.2 Ghz overclock - his LDT mult was on auto and he could not go past 230 Mhz, once he dropped to 3 he manged 2.9 Ghz.
Had he upped his LDT voltage he may have gotten stable past 1000 Mhz, the auto detect on the board wasnt working right.
So unless your LDT is over 1000 Mhz you should not have to up that voltage.
Not SuperPi.Quote:
Originally Posted by Daved+
But my Opteron 175 failed dual prime95 at 2.7 GHz after 20 hours.
I then set LDT voltage to 0.1 Volts more, lowered to 2695 MHz and run other RAM and it was now 48 hours stable. Of these factors the LDT voltage is a likely candidate to be responsible for the improvement.
I didn't cross-check the other factors. These runs were both with 4 GB RAM and the DFI board doesn't support ECC, so the prime fail can as well be a bit flipped in one of the RAM sticks.