Radeon 7750 for Litecoin / Dogecoin / Scrypt / Cryptocurrency Mining

Some notes on using a 7750 for Dogecoin mining. Should be relevant for any Scrypt-based coin such as the popular Litecoin. I’m using cgminer 3.7.2 which is an old version, but the most recent version of cgminer to support scrypt based mining.


I found that I needed to set my fan speed to 100%. The 7700 series seems to desire much cooler temps than other cards. Mine is happiest at around 63 degrees Celcius. Above 65 seems to hot for it and it produces too many HW errors. Other cards I’m using are fine at around 75C.

I find it very hard to eliminate HW errors entirely. I think they’re bad because too many affects the quality of your hashing and can eventually damage your card. I can find very little information on acceptable HW error rates, but one guy says he shoots for below 1% of your A and R added together. Update: A reader sent in his settings, which hash slightly faster than my own setup but have no hardware errors at all. 

Let’s do the math quick. 7888 (accepted hashes) plus 128 (rejects) = 8016. Divide by HW errors (12) to get 0.15% Well below 1% so I called it good enough.


But if you bump intensity ( the “I” figure) up from 14 to 15, HW errors start to multiply like soldiers after the war. This is a low-intensity card, which is why no one buys it specifically for mining. But if you happen to already have one lying around it makes a great casual miner when you’re not using it.

Here are my batch file settings for minimal HW errors for zero hardware errors. Text in light blue needs to be replaced by your own figures. When I want to be able to use my desktop and watch youtube videos I set gpu-engine to 870. This setup should hash at a stable 166 kh/s. Thanks to Paul for sending in these new settings which are better than the ones I was using.

cgminer –scrypt –gpu-engine 935 -I 11 –thread-concurrency 2560 –gpu-memclock 1200 -w 256 -g 2 -o stratum+tcp://MINING-URL -u WORKER -p PASSWORD –failover-only -o stratum+tcp://MINING-URL  -u WORKER -p PASSWORD

Link to specs and more

advice about this card.

The cheapest cell phone plan in Canada

Since moving to Canada in 2006 I’ve struggled to find a good deal on a cell plan. I started with Fido, which got bought by a big 3 – then switched to Koodo later on – which also got bought by a big 3.

That seems to be a big problem in Canada. A small upstart cell provider will come along with decent prices and decent service, before promptly being absorbed into a giant communications conglomerate hungry for more “shareholder value.”

Consistently the cheapest plans have been from a hardly known carrier that continues to fly under the radar year after year. 7-11 speak-out wireless.

With speak-out, the time you buy doesn’t expire after a month like it does with all other pay-as-you-go providers. Top up once, and you’ve guaranteed yourself that phone number for a year. It’s the perfect plan for casual phone users such as myself who only use a cell phone for travel and emergencies. At all other times I use either a landline or VOIP.

With a minimum time purchase of 25$ it only costs $2.08 per month to keep your account open. The next best option Virgin Mobile costs 15$/month with its minimum top-up or $8.33/mo for it’s 100$/365 day topup.


You can use any SIM-capable phone with their pay-as-you go plans costing 25 cents a minute for the most basic plan. This is the cheapo phone my brother got when he started using SpeakOut. As an independent contractor he needs to have a cell phone at all times. He claims it only needs to be charged once a month.

7-11 is slowly updating their geriatric plans with data packages that beat all others I’ve seen in their pricing. But the best idea in Canada is always to avoid using data as much as possible anyway.

SpeakOut is a no-frills, no-bullshit and no-advertising alternative to the worst cell phone landscape in the world.

Canada Cell Plan Links

Speakout 7 11

SpeakOut has the best cell phone plan for someone who sees a cell phone as a necessary evil and would rather use it as little as possible. At 25 cents a minute flat rate, their per-minute billing is far superior to the more common 35 – 45 cents a minute rates of other providers.

Virgin Mobile

I used Virgin for a few years when I thought it was the best option for me. They have an unpublished promotion where they double your topup credit after a number of months with no activity. Works well for me  because I only travel once or twice a year for conferences which is when I turn my phone on.

Wind Mobile

Wind is probably the best carrier if you live in a major city and only call people in that same city. Unlimited local calls for 20$/month but it suffers from the same outrageously priced addon bullshit that makes the bigger carriers so unappealing. 8$ extra for a bunch of basic features that should be free and are free with prepaid plans.

For The Others, Consider their Advertising Budgets

It’s a good idea to realise that the big 3 cell phone carriers spend obscene volumes of money on advertising. You have to consider that just like it does for any product or service, advertising drives the price up. When you agree that you will pay Rogers 80$ or more per month for the next 2 years, you are crowdfunding their TV ads. So for a better deal, look to companies that don’t advertise or only advertise minimally.