Archive for the ‘Tests and Reviews’ Category

kepler-bios-tweaker-gtx-750-ti-tdp-power-limit

Nvidia is advertising their new GeForce GTX 750 Ti GPUs based on the new more power efficient Maxwell architecture as being with 60W TDP, but in truth they seem to be much more power efficient than that. A lot of people are already interested in using these new GPUs from NVidia for mining, because the performance that the Maxwell delivers seems to be very good in terms of hashrate per Watt ratio. When you use CUDAminer to mine with the GTX 750 Ti you will notice the card will quickly reach the 100% power target limit and normally you are not allowed to increase the power limiter of the card above the 100% value, you are allowed to only lower it further. The interesting thing here however is that the default TDP limit for GTX 750 Ti is actually set to 38.5W inside the BIOS and the minimum of 78% you can go down to is equal to just 30W TDP and as we’ve mentioned Nvidia is talking about 60W TDP for these cards. The fact that the cards are actually limited to 38.5W by their power limiter is something that can prevent you from squeezing the maximum performance that you can get by overclocking the GPU and/or the video memory of the card, so increasing the TDP limit by modifying the BIOS and reflashing the video card with the modified BIOS can help you with that.

Since many of the GeForce GTX 750 Ti video cards do not have external PCI-E power connector you will be limited to the maximum power that these cards will be able to use due to the 75W maximum of power that PCI-E x16 slot can provide by specifications (66W for the 12V line that you will be actually using, the other ~10W are for the 3.3V line). But even this will provide more than enough headroom since the default TDP limit is not 60W as we though, but really just 38.5W, so lots of headroom for overclocking. In order to be able to modify the BIOS of your video card you will need to first save the original one from the card, you can use GPU-Z for that and make sure you keep the original BIOS as a backup and save the modified one as a separate file (you can also backup the BIOS with the nvflash under DOS if you are having trouble with GPU-Z). Then you need to fire up Kepler Bios Tweaker and open up your BIOS file and edit is as shown in the screenshot above (left is original, right is the modified) in order to get 65.5W as the maximum TDP of the card. After that you need to flash the BIOS back to your card using the provided nvflash, you can download the flasher and the Kepler Bios Tweaker along with a standard BIOS from a reference 750 Ti and a modified version of that BIOS to allow 65.5W TDP from the link below. We suggest that you save the BIOS from your own video card and modify it, also do have in mind that modifying and flashing modified video BIOS to your video card can be dangerous, so you should be extra careful what you are doing and not modifying things that you should not or does not know what they are for!

gtc-750-ti-tdp-limit-increased-afterburner

The procedure described above will work for increasing the power target limit on other video cards as well not only on GTX 750 Ti, however before increasing the limit make sure that your video card cooling can keep the card cool enough. Using the video card fro mining will bring the power target to 100% in most cases even without overclocking the card additionally, so just by increasing it you might e able to squeeze some extra performance even without overclocking it further. The version of nvflash provided in the archive below is the latest one that will work with the GTX 750 Ti as well as with older video cards, it is the DOS version of the flasher as the Windows version of nvlfash does not seem to work properly – it does not want to flash the modified BIOS to the card saying that the BIOS digital signature is wrong. No problems flashing the modified video BIOS though trough the DOS version of nvflash 5.163, so we have only included the DOS version that will work with the method described above. There are two BAT files configured to flash the modified video BIOS and to restore the original version of the included reference design board BIOSes, you just need to run “nvflash your_bios.rom” and confirm with “y” when asked by nvflash (make sure you’ve made a backup of your original video BIOS first!). Again, be aware that video BIOS flashing and modification can be dangerous and can temporary render your video card useless, at least until you reflash it with the original BIOS, so do keep a backup of the original! Also note that increasing the TDP limit beyond the recommended value above could also be dangerous, so be well aware that this modification can be dangerous! Feel free to share your results for overclocking and mining hashrate after increasing the TDP limit of your GTX 750 Ti or another board in the comments below.

Download the Kepler Bios Tweaker tool and nvflash for modifying your video BIOS…

btc-robot-intro

We have been testing the BTC Robot automated Bitcoin trading robot for a few days and we went for the Silver plan that gives you a downloadable version of the software to use on your own computer. We have already described some of the issues we’ve went through using that version as you can only install it on one computer and not move it to another later on (unless you contact the support and request you want to do that). We have also had some trouble making the automated trading software work properly on Windows, even though it should be supported. As a result we would recommend to go for the higher plans that will give you a cloud based version of the trading bot that you can access and use from different computers and that will be online all the time, so yo don’t have to keep your computer online 24/7 like you need to with the Silver Plan and the downloadable version.

Furthermore, due to the fact that the BTC Robot trading algorithm relies on data coming from MtGox and that exchange has been having some trouble lately and things are really crazy with the exchange rate there for the moment the market situation is preventing the bot from executing trades properly. That is precisely why we have decided to test another advertised feature of the software – 60 days money back guarantee. We have requested a full refund and now, 2 days later we have just received our payment back. We have used BTC to pay for the Silver Plan and we got BTC back in our account, though the amount is a bit less than what we have sent as apparently the payment processor takes into account the exchange rate at the time of payment and refund. The refund took about 2 days to process and us having back the money in our BTC wallet after making our full refund request as per the 60 day money back guarantee. So that works pretty good as well and it gives you the ability to test the BTC Robot automated Bitcoin trading robot for a few days and if you are not happy you can get your money back. Kind of works like a trial version, so you can test the software and if you are not happy with it to get your money back.

Check out our initial thoughts about the BTC Robot automated Bitcoin trading robot here…
And some more information about the BTC Robot Automated Bitcoin Trading Robot here…

leaserig-mining-rigs-for-hire

LeaseRig is an interesting new service that allows you to rent mining rigs for a limited time period that will mine for you in your preferred pool and your preferred crypto currency for the duration of the lease. There are mining rigs available for Scrypt, SHA-256, Scrypt-Jane, Keccak (SHA-3), Scrypt-A-nFactor and DRKMix (Darkxoin mining). These rigs are provided by users and the service LeaseRig only connects you to the mining rig providers, processing payments and acts as control and monitoring panel. Everything seems very quick and easy to start using the service if you want to rent mining rigs and there are already quite a few available, and we were very excited at first. This is precisely why we have decided to give the service a try by renting a mining rig for 24 hours to be able to actually test how things are working and give you adequate feedback and to make a proper review of the service.

rig-leased-for-24-hours

In order to test the service we have decided to lease a smaller mining rig for longer period of time, so we choose one that is with 0.62 MHS and have rented it for 24 hour time period. The cost for leasing the rig for 24 hours was 0.01070000 BTC (you can pay only in BTC), and estimating the LTC return rate for 24 hours of mining Litecoin with that hashing power was roughly 0.1945 LTC (0.00485666 BTC). This means if we used the rig to mine LTC the profit we would get will be about half of what we have payed for renting the mining rig, so we have decided to go for the currently more profitable DOGE. The projected mined crypto with that hasrate for a day by the pool (Coinotron) was about 2600-2700 DOGE or up to about 0.00567000 BTC with the current exchange rate. Again less than what we have to pay for renting the mining rig, but we decided to give it a try as we were actually willing to test the service… you can find better prices for higher hashrate and with longer lease time you can end up with profit according to calculations.

rig-leased-for-24-hours-2

Everything started very good, the BTC deposit has appeared and was available for use very fast. We have hired the mining rig, removed the rigs default pool settings and set our pool and worker settings for mining DOGE at Coinotron and in a moment the rig started working. For a few hours everything was running smooth and problem free, so we stopped checking the Mining Rig status every few minutes and a few more hours later we checked to see if everything is still fine and it was not. The mining pools and settings were back to the default ones for the mining rig we have rented and it was not mining to our pool (it was gone from the list of pool) and was mining for the rig owner with more than 12 hours left from our contract. This has probably continued for an hour or two at least before we have noticed it, we again changed the pool settings to ours for mining DOGE in Coinotron and have removed the default ones. After that going for some sleep and waking up in the morning and checking the status with just about 2 hours more left from our lease the rig was again back to the default pools and our mining pool info was not in the list and it was not mining for us. This meant that again the rented rig was not mining for us for at least a few hours, again setting the proper settings for the remaining time of our contract and there were no more problems until the lease time has finished.

leaserig-coinotron-actual-mined-doge

The result from our 24 hour rent of the mining rig was really awful. Instead for the projected 2600-2700 DOGE getting mined for the lease time, we ended up with only about half of that actually mined or about 1300 DOGE. This means that due to the two times that our pool settings were gone and the mining rig was not mining for as as per the contract before us noticing has totaled in probably 12 hours. This is really unacceptable, even though after our contract has finished we can still see the leased mining rig mining for us at the Coinotron pool with a slightly lower hashrate for about an hour already we are still not happy at all.

After reading a bit more, it seems that the problem with the pool settings getting reverted back to the default set by the mining rig operator can happen if you restart the miner on the rig and you need to manually reset them to your own settings each time. So if the mining rig does not get restarted or the miner software on it at least you might not have the problem with the pools reverting back to the owner of the rig, but in hour 24 hour test we have noticed this happening 2 times (maybe even more) and thus resulting in really very unsatisfactory performance of the service. You cannot expect the people that rent the rigs to be monitoring them all the time during the lease period, especially if you rent multiple rigs and for longer periods of time in order to quickly react should a problem with the pools reverting form the user set ones to the rig’s defaults.

The conclusion: we have started by renting a 0.62 MHS mining rig for 24 hours paying 0.01070000 BTC, we have mined Scrypt crypto and more specifically DOGE as it has higher profitability than LTC and at the end of our lease we have ended up with the equivalent of 0.00252630 BTC. So we actually have payed 4 times more than what our actual mining earnings are worth and that is clearly not going to make us recommend the LeaseRig service. We have ended up with half of the expected DOGE mined because of a problem with the system that reverts the mining pools to the mining rig’s defaults instead of using our mining pool and worker, so this has essentially halved our expected earnings. So for now you better not go for the LeaseRig service, until at least they figure a solution to the problem with the pools getting reset. But even without that pool issue we have experienced it is hard to go for a lease of a rig that will not only cover what you have payed for renting it, but will end up with some profit for you! You could actually be more interested in becoming one of the mining rig providers and earn some cash for leasing your mining rig equipment, because this actually seems more profitable than to be renting rigs.

Other similar services offering Renting of Mining Rigs or Hashrate:
MiningRigRentals
Nicehash


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