Bitcoin Forum

It seems to me if GPU or FPGA will be useless mining bitcoin that they might look at mining on alt chains provided there is some return rather than selling the cards. Can you mine alt coins with an ASIC ? It seems if theres a change in the algo they are useless ?

but namecoin isnt a change in algo last time i checked, it was just a seperate chain

Interesting.  Seems if a minority do merged mining then using ASICs for namecoin could have very interesting returns.

Can you even merge mine using ASIC's ?

sure. the merged mining part is done on the pool side. just point your gpu/fpga/asic/quantumwhammomatic/whatever at a merged mining pool, it does the rest.

What do ASIC mine scrypt like ?

I have been buying up LTC on the speculation that GPU rigs will start mining litecoin once ASICs increase the difficulty of BTC.

HOLY MOLY !

I think you might be onto something here mate !!!

Thanks for the tip !

Great minds think alike   :)

The adoption of ASIC by bitcoin miners will push GPU and fpga miners somewhere else. My thinking is it will be litecoin because namecoin is merge mined.

Protip: Buy/Mine all the  litecoins you can before October.

+1 Agreed. I think you will see a rise in price for litecoins over the next 12 months.

You won't see 1 cent increase unless they make Silkroad for litecoin.

Now theres an idea....

Make something better.  How about Litecoin amateur dentist/surgeon.  Get your titties lifted and your final lady-boy transformation done without all those pesky rules.  Maybe sell some organs too.  How much is a kidney worth in Litecoins?

They are about 40 grand in USD so "a lot of ltc"

I can't speak for adoption rates but I can speak to whether ASICs can be used on alternate chains.

Any ASIC built to mine on the Bitcoin network can also mine any altcoin for which the algorithm(s) have not been changed. Since Namecoin uses the same algorithms as Bitcoin, Bitcoin ASICs should be able to mine Namecoins - the vast majority of the altcoins didn't change algorithms, actually, so the same is true for them. There are a handful of altcoins, Litecoin and Tenebrix included, which moved to scrypt() as a replacement of sha256() for one step in the process. ASICs won't work for scrypt-based altcoins, nor is it likely that ASICs can or will be built for them: the entire point of scrypt and bcrypt was to make a difficult-to-accelerate algorithm, and by design the amount of die space an scrypt ASIC would take makes it prohibitively expensive even beyond normal ASIC manufacturing costs.

Great input. But would it be possible to use FPGA's for Litecoins? Can it be configured or modified for Litecoins?
Its very hard to believe that CPU's and GPU's are going to be the best for scrypt-based hashing.

I imagine so as they are programmeable. Has anyone tried to use them for litecoin yet ?

Scrypt is easily mined by anything with high integer processing power and high memory bandwidth... The latter is most often lacked by fpga devices like we see used to mine bitcoin. As high memory bandwidth is very important to gpus for 3d applications, gpus will probably remain better than anything else for hashing Scrypt in the next long while. For instance, the spartan 6 fpgas have memory bandwidth amounts an order of magnitude smaller than current generation amd gpus.

FPGAs are essentially programmable ASICs, the only meaningful difference is size and price point. FPGAs tend to be larger than ASICs and cost much more per chip. ASICs tend to be smaller and cheaper than FPGAs but you can't purchase just one, minimum order size tends to be massive because the manufacturing process has huge initial costs - once those initial costs are outlaid, however, they become quite cheap to re-manufacture new batches of. The only reason ASICs are just starting to hit the Bitcoin market is because it's taken this long for someone to amass and be willing to front that initial cost.

In short, if you can do it with an ASIC you can probably do it with an FPGA (some slight limitations/differences, but none that important). Scrypt, and therefore Litecoin, is highly resistant to GPU, FPGA and ASIC acceleration because of its high memory requirements. See this StackExchange question for more details: http://bitcoin.stackexchange.com/q/1305/22

Yeah, NMC uses the same algorithm as bitcoin, the only difference is that it has a different use to bitcoin (i.e. buying .bit's)

I don't buy this argument.

Quote from scrypt.c:

const int scrypt_scratchpad_size = 131583;
char scratchpad[scrypt_scratchpad_size];

Quote from XC6LX150 data sheet:

Total Block RAM (kb) = 4824

converting bits to bytes I'm getting 617472, which would make litecoin hasher easily fit into the popular Spartan-6 chip already in hands of many miners.

Reality is people are probably mining with FPGA on LTC already but they are not telling the rest of us.

Just like SC crew were GPU mining LTC and not telling. Of course, the first LTC GPU miner was ArtForz loser just like with BTC he reaped all the profits and raped the rest of us stupidotos.

Bro...seriously...you are the only "stupidoto" around here!!

I don't have much experience with FPGAs, but two questions come to mind.

1. How fast is this RAM? Is it fast enough to compete with the L2 cache of modern CPUs?

2. GPUs manage to compensate the lack of local memory by means of massive parallelization, but a lot of global memory is required to do this. If I'm not mistaken, this global memory usually consists of GDDR5 SDRAM, which is still relatively fast. Would it be profitable to make an FPGA with that much quality SDRAM, or would it be cheaper to just get a GPU instead?

Pooler, I wouldn't say that it requires a lot of global memory to get it working.
My 69XX cards are pulling 500KH/s each, these settings are used for 512MB buffer. "(lookup_gap 2) (gpu_thread_concurrency 8192.)" It will use +500MB of Dedicated VRAM when running.
Now, I was trying to get Reaper running on my laptop. I had to lower the worksize to 64, gpu_thread_concurreny to 768 and increase lookup_gap to 8 to get my HD 4670 Mobility running. Its working now and pulling 40-50KH/s and its only using 12MB of VRAM. Yes, only 12MB and I think it can run on less than that. Also that poor card has very low memory bandwidth, 25GB/s.
I more than sure that modified FPGA's can mine litecoins and we don't need super fast bandwith and huge amount of global memory.

~R.H~

First of all Spartan-6 by itself isn't something that would compete with modern CPU. This is a 45nm device targeted to be cheap and power-efficient.

The absolute maximum for clock is 1080MHz, but only a fraction of the device can run at this speed because the chip doesn't have the heath spreader.

Internal block RAM is a dual-ported SRAM rated at 320MHz zero-wait-state access. When people synthesize soft-CPUs on Xilinx FPGAs they use it as L1 cache or simply there's no cache and the whole RAM is 536kB that is on chip.


Spartan-6 LX150 has 4 memory controller blocks that can control single-chip external DRAM (DDR, DDR2, DDR3, and LPDDR) up to 800Mtps.

But currently only ztex (and maybe Enterpoint) make boards that have external DRAM chips, and those aren't the boards in the hands of most miners.

Besides, emulating CPU or GPU in FPGA isn't the architectural road to take the advantage of the famed power efficiency of the FPGAs. Those devices achieve their optimum efficiency at relatively low clock speeds by doing maximum usefull work per clock and minimizing the on-chip logical resources that aren't used.

I wouldn't say "highly" in absolute terms, but I do think it is much more ASIC-resistant (in terms of cost-effectiveness) than SHA-256.

In practice, an SHA-256 ASIC needs no memory at all. The non-negligible memory requirements of scrypt, on the contrary, make CPUs and GPUs more similar to an ideal scrypt ASIC, because fewer of their components are "useless" when it comes to hashing.
The simple fact that a scrypt ASIC would need to resemble more closely a CPU by having relatively large amounts (N * 128 kB) of random-access memory would, logically, make it more expensive than a zero-memory SHA-256 ASIC achieving the same speedup over existing CPUs.

I'll have something to roll my pumpkin futures profit into!  I've been buying steadily and watching the price rise.  It think it should peak around November or December...

this may be a really stupid question, but what is ASIC mining and why is it important?

application specific integrated circuit

ok thanks,  but what does it mean in practical terms?  why is everyone talking about it?  what effects will it have on the bitcoin world?  thanks in advance!

CPU : GPU :: GPU : FPGA :: FPGA : ASIC

As the market matures, mining will progress towards more and more specialized hardware. This will allow for a greater hashrate given the same price.

CPU is general purpose
GPU is for several specific applications (mostly games)
FPGA is for even fewer applications, great at crypto
ASIC models will be made specifically with Bitcoin in mind

Bitcoin ASICs are controversial because at first one company will have a temporary monopoly on their manufacture. Expect a big boost in hash rate, and more people complaining about that monopoly until more manufacturers enter the market. Since this makes CPU even MORE obsolete, expect fewer botnet miners and more professional miners with lower profits - which in the long run goes to zero.

Really it sucks for miners but is great for users. :)

Ok, thanks.  Very informative.  Why is it good for users to have a boost in hash rate?  Also, I still don't understand what ASIC is, it's better hardware that's designed specifically for mining bitcoins?  It involves better software too or no?  What makes ASIC so much better?  How much faster will it be at mining?  Is there some place where I can read lay discussion of this issue, I'm not that technically advanced.  Thanks!

A higher global hash rate usually means a more secure network (assuming the hardware is not used against the network, of course).

Yes. It is much faster and more power-efficient.

No, it's a purely hardware thing.

https://bitcointalk.org/index.php?topic=87934.0

Thanks, very helpful!

Does anyone know if the USB coffee warmer thing will work with macs?

Does anyone know when the ASICS being produced will hit the market approximately?

Are they being pre ordered now?

Apparently they are supposed to start shipping in october. There is a preorder form on bfl site.

I havent mined since you could do so with a cpu  :D

So this is my prediction, that when early November rolls around and many of the ASICS have been delivered and put to mining bitcoins and with all the market fluctuations that will happen with this being an election year around the same time I suspect the difficulty of bitcoin will rise dramatically. Price is a variable because it could rise before in anticipation of the difficulty rising.

Should be an interesting second half of 2012 in the financial markets as well as the commodities and cryptocurrency markets.

At least your coffee will be warm. Dont know about your wallet :)

HOLY MOLY! I just seen this http://www.butterflylabs.com/order-form-bitforce-sc-mini-rig/ (http://www.butterflylabs.com/order-form-bitforce-sc-mini-rig/)

They will be delivering 1000GH/s rigs? Damn! For $30k USD!

I can see some wealthy BTC peeps buying a few of these and skyrocketing the BTC difficulty overnight!

Right now hash rate is 12,450 GH/s.

Wow...talk about scaling up!

 ;D ;D ;D ;D ;D

Welcome to last week. Enjoy your stay.

Uhhh okay yeah i dont read every post on this forum bro lol