Max HT link speed?

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cyclone3d

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So I know everybody says to keep the HT link at or below 1000Mhz for whatever reason.

Well, it is running at 1286Mhz on my system.

I'm doing a bit of testing with the max speed of different stuff on my system.

Anybody have there's faster?

 
I've actually found that overclocking the HT link speed to higher levels to be pretty harmful to my system. I've got an ASRock 939Dual SATA2 with a X2 3800+ at 2.3 and whenever my HT link speed goes too far above spec I start to see random bluescreens and actually would cause my USB link to my external HD to die randomly (the old windows delayed write to $Mft failure) and some other odd behavior that at first I could not for the life of me figure out. I thought this was just due to memory overclocking so I put my FSB close to default and the problems still happened until I manually turned down the HT link speed. This may just be a case for my board and its chipset specifically, but the benefits you will gain from overclocking the HT link will be pretty negligible anyway. I wouldn't recommend going any higher and if you run into stability problems then just stick it back to 1GT/s and leave it.
 
Well... I think it is working fine at this speed. A while back, I had actually tested it for quite a bit at 1200Mhz and it never gave me any problems.

I did have to raise the HT link voltage to 1.35 to get it to work properly at 1286 though... at 1.30 it was fine at 1276... but 1286 spazzed out in Orthos. I got some freaky lock up where my computer made a whole bunch of sound out the speakers and lines were showing up on my screen.... started at the top and worked its way down.

Oh.. and the graphics in CIV 4 seem to be running a bit "smoother" with the HT link cranked all the way up.. Sisoft Sandra shows almost no improvement whatsoever though... except if you look at the screenie I took, it shows the interconnect latency at 75ns instead of the stock 98ns.
 
What motherboard you using, the only one im aware of that could do over 1000 HT is the ATI based dfi 939 boards, all NV boards stop around 1010-1050.
 
There is absolutly no reason to overclock the HT unless your goal is to merely have an unstable system, or get closer to an unstable system. The performance gain will be zero. The performance difference between 800 and 1GHz. Even at 400MHz, it has more than enough bandwidth for a single socket system and there is no performance difference.
 
I hit 1400 on my A8N-SLI at one point... (280x5) but it made *no* difference.

Alas, I have no screenshots or anything of it.
 
Same ive hit 1200 odd no problems but i turned the multi down as people say it can corrupt the hard drive or something. :confused:
 
RamonGTP said:
There is absolutly no reason to overclock the HT unless your goal is to merely have an unstable system, or get closer to an unstable system. The performance gain will be zero. The performance difference between 800 and 1GHz. Even at 400MHz, it has more than enough bandwidth for a single socket system and there is no performance difference.
Click to expand...

qft

there is no real performance benefit to running your HT link beyond spec. The only reason most people run theirs at or below 1 Ghz when overclocking is to ensure stability (although it certainly is possible to run a stable system with it beyond spec, it's easier to eliminate that variable by running it at or below spec).
 
RamonGTP said:
Even at 400MHz, it has more than enough bandwidth for a single socket system and there is no performance difference.
Click to expand...
Funny you should mention that. I have also tested all the HT multipliers vs performance and 3x (600MHz DDR = 1200MHz) is where performance starts leveling off. Performance is choked off at 2x and 1x, at least in the multi-threaded benchmark I ran.

In the same thread someone posted some Doom3 benchmarks with HT at 1x-5x and performance was flat for a single core CPU. I guess it depends on the program and number of threads and cores (and possibly the GPU as the limiting factor).

Unfortunately the search isn't working correctly right now so I can't search back several months for that thread.
 
pxc said:
Funny you should mention that. I have also tested all the HT multipliers vs performance and 3x (600MHz DDR = 1200MHz) is where performance starts leveling off. Performance is choked off at 2x and 1x, at least in the multi-threaded benchmark I ran.
Click to expand...

Here is Eclipse's investigation: [link]
 
quadnad said:
Here is Eclipse's investigation: [link]
Click to expand...
I think he's the one who ran the Doom3 benchmarks in the other thread,

I do agree that overclocking HT is pointless. It's not a bottleneck. But I disagree what the minimum is under a heavy multi-threaded load.
 
Simpson5774 said:
What motherboard you using, the only one im aware of that could do over 1000 HT is the ATI based dfi 939 boards, all NV boards stop around 1010-1050.
Click to expand...

I'm using an Abit AN8-Ultra, with the newest BIOS.. which has been modded by Rebel's Haven.

The board I used to have, ran fine with the HT link over 1Ghz also.... it had the ULI chipset in it.
 
Simpson5774 said:
What motherboard you using, the only one im aware of that could do over 1000 HT is the ATI based dfi 939 boards, all NV boards stop around 1010-1050.
Click to expand...
I did 2504MHz (1252MHz DDR) with a cheap-o ECS nForce4 board. I think the later NF4 chipsets were overclocking a lot better, but it was never as bad as only 1010-1050.
 
pxc said:
I did 2504MHz (1252MHz DDR) with a cheap-o ECS nForce4 board. I think the later NF4 chipsets were overclocking a lot better, but it was never as bad as only 1010-1050.
Click to expand...

I remeber for the longest time of the DFI ulra/sli-D holding the record at xtremesystems for highest HTT and it was like 1055 or something real low. When the CFX3200-DR/G, the dfi crossfire board, anandtech did a review of it, and they were able to go up to like 1400mhz on the HTT where no other nf4 mobo went to.

I sort of stopped following socket 939 after that,

AMD killed off a perfectly good socket and platform no good reason

My dfi board in sig can only do 1020mhz till it fails. .
 
pxc said:
I think he's the one who ran the Doom3 benchmarks in the other thread,

I do agree that overclocking HT is pointless. It's not a bottleneck. But I disagree what the minimum is under a heavy multi-threaded load.
Click to expand...

yeah, i can't do multithreading without a multicore proc. :(
 
i just picked up a new Asus M2N-E X2 AM2 4800+ and using asus's ai overclocking it sets my HTT to 1100 220 x 12.5 and it is sick stable all at stock voltages and cooling, orthos, prime95 gaming all run great and i saw nice improvments in sandra cpu and memory benchmarks. can anyone suggest a multi-core benchmark thats free i can test things out with? other than sandra
 
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