Wednesday, 7 March 2018

8GB or 16GB of RAM for Heavy Multi Tasking

8GB or 16GB of RAM for Heavy Multi Tasking - Intro

RAM is fairly cheap and easy to install. But how much do you need for heavy multitasking?

8GB or 16GB of RAM for Heavy Multi Tasking - Observations

Prior to my upgrade I was running 4GB of RAM, but owing to 32 bit limitations of 3GB and two 500MB graphics cards, I can only see 2GB of available RAM in performance manager.

This 2GB of RAM was always maxed out, hovering around the 1.8GB mark most of the time during day to day use. I use a 4 monitor set up so can have a awful lot of stuff open.

I recently upgraded to a 64 bit system, and so now I can use more RAM. I have installed 16GB, but how much of this will get used.

Typically I have open:

  • 4 Browser Windows (3 or 4 Tabs Each)
  • 3 MS Word Windows
  • MS Outlook
  • >10 Large PDF Files
  • MS Publisher with lots of Photos
  • Modelling Software or,
  • Sketch Up or,
  • AutoCAD
So how much memory does all this stuff take up? Just 3.67GB:

Windows is actually using a lot more memory standby memory, if we look in resource monitor we can see only 1.4GB Free with around 11GB used in standby. Standby memory hold on to applications that have been closed, in case they are needed again, this will gradually "fill up" the longer you have your machine switched on and you open and close programs.

8GB or 16GB of RAM for Heavy Multi Tasking - Conclusion

8GB will almost certainly be plenty for heavy multitasking. Any more than 8GB and really you are looking at server amounts of memory that give no real benefit. 

Would I have bought 16GB of RAM knowing what I know now? Probably not. But its would still be tempting because the more available memory for standby the better. . . . and there in lies the rub.

As a note aside the best performance upgrade you can ever make (in my opinion) is a solid state drive SSD. Even a old, low spec computer will work twice as fast with an SSD.  

Monday, 26 February 2018

Getting the Best Price at a Builders Merchants

Getting the Best Price at a Builders Merchants  - Intro

For some a trip to a builders merchants may be a daunting prospect. There are a few things to consider before you go as they are not like other shops.

If you have ever been in a builders merchants like Jewson, Travis Perkins or Buildbase, you will notice that the prices (if they are labelled at all) are normally high. Unless you are looking at a special offer price, then you are likley looking at the list price.

Quick Guide 

Getting the Best Price at a Builders Merchants - Ring for a Price

Most products have a List Price. The list price is a made up price that a builders merchants will put on a product hoping that somebody will pay it. The price you "can" pay for the product is often a lot lower.

So the key is to ring up and ask for a "quote" (price) on what you want before you go to the actual "shop". When you have a price, try to negotiate a lower one.

Getting the Best Price at a Builders Merchants - "Better Price Please"

Prices are not fixed, you can try and get a better price. Some staff will do this straight away because they are nice people, others are too lazy or do not care if you pay more.

The conversation might go like this:

You: "Hello could I have a price for 100 concrete blocks please"

Builders Merchant: "We can do those for 75 pence each"

You: "Is that your best price please?"

Builders Merchant "The best we can do is 69 pence a block"

You: "I will be getting some prices elsewhere so is this really your best price?"

Builders Merchants: "Yes" or "we could do them for 68 pence a block"

It is important to do this for everything you intend to buy. If you are building a wall for example, get prices for sand . . . cement. . . even a trowel and bucket before you go to the shop. EVEN get a price for a role of string. . . otherwise you might pay £6 for it.

Getting the Best Price at a Builders Merchants - Get Price from Two Companies

Jewson (by example) might offer your concrete blocks (best price) for 68 pence each. If you then ring up Travis Perkins (by example) and say that Jewson will do them for 68 pence then they will either say:

  1. "Thats a really good price we can't match that"
  2. "We can do them for 65 pence"
You can even then go back to Jewson with the new lower price from Travis Perkins and see if they will beter it. In short it is very time consuming so it is best to email list to each Builders Merchants.

Getting the Best Price at a Builders Merchants - Delivery

After you have your best price, ask for free delivery. This is an added bonus that is nearly always included for fairly large orders. 

Getting the Best Price at a Builders Merchants - Get the Quote in Writing

It is very important that you get the price or quote in writing. If you just talk to somebody over the phone, then that is not good enough. You may not get that price when you pay! Which would be annoying.

Also if you have a credit account (see notes below) then you will not pay for maybe a month, by which point you will need you email to check the bill or invoice, against your quote. 

Getting the Best Price at a Builders Merchants - Check Price

If you are paying cash or card on the day then then obviously check the price as you normally would. But if you pay by invoice then make sure when the invoice arrives (may be 2 weeks after receiving the goods) that you check the prices. They sometimes may have doubled! And you will be very glad you have your quote in writing (email). 

Getting the Best Price at a Builders Merchants - Credit Accounts

Where things really fall apart is the accounting. You might think a credit account is a handy thing to have, but you will be harassed (record is 8 emails and 2 calls over 10 working day period) by their "partner" credit management companies, to pay the bills pretty much from the word go. Even for small bills under £100. . . 

Personally I try to make money by actually working and doing things, not skivvying around trying please somebody in a call centre. 

Jewson for example will not email invoices to you so you can check them easily, instead its masses of paper, or some inconvenient online portal where you can log on (yes another password to remember) to view them.

Getting the Best Price at a Builders Merchants - Conclusion

For large orders a builders merchants can save you a lot of money. However, these guys make buying something time consuming. This may be worth it for large order but for small bits and bobs, you may prefer to  go to B&Q or Homebase. 

Always look out for special offers in Homebase or B&Q, they are often cheaper than a Builders Merchants.

Wednesday, 21 February 2018

Does Microsoft Office USe Multiple Cores?

Does Microsoft Office Use Multiple Cores?

Having recently upgraded from a 4 core to 8 core system, I am wondering how well access (by example) uses multiple cores.

So whilst transferring a 65,0000 entry access database to excel, I have observed the below CPU behaviour.

So besides showing I need more memory, the performance monitor shows that work load is spread over 4 cores, possibly 5.

Changing priority of the process does not change this spread. A lot of people say that you don't need more than 4 cores unless you are doing crazy rendering or editing. They are probably right!

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Monday, 19 February 2018

Scythe SY1225SL12L 120mm Review

Scythe SY1225SL12L 120mm Review - Intro

Around 2 years ago I decided to make my PC quieter by using 2 Scythe SY1225SL12L 120mm Fans to replace the main chassi fan and also to replace 2 smaller CPU cooler fans.

Very Normal Looking

I run a HP XW8400 with two dual core processors, with thermal output of 60W a piece. This arrangement worked well for 2 years. I occasionally run CPU intensive models, the rest of the time its just multitasking and PDF making.

Scythe SY1225SL12L 120mm Review - Noise Levels

The fan is almost silent run at 12V this fan spins at 800 rpm. It is so quiet you have to listen hard even to hear it. It is quieter than the Arctic Cooling F12. But the air flow is lower. . . . regardless of specs, you do not feel much air going through case with these fans. After a switch back to Artic Cooling F12 there was a notable draft going through the case.

Cobwebs - The BAdge of Long Service

Scythe SY1225SL12L 120mm Review - Cooling

As mentioned above one of these Scythe SY1225SL12L will adequately cool 2 60W processors under light use. It will not cool 2 x 120W processors. I recently upgraded to 2 quad cores and even at idle the fan could not dissipate that much heat.

Scythe SY1225SL12L 120mm Review - Conclusion

The Scythe SY1225SL12L is a well made, excellent value fan, which is virtually silent. It is a great options for those wishing to build a nearly silent PC.

0.03A - Very Small Power Consumption

The fan is quite partly because of the design of the thing, but mostly because it spins a lot slower than most fans. As it spins slower it moves less air. If you are using over a 100W processor then chances are you will need more air flow, even when run on 12V.

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Friday, 2 February 2018

Reinforced Retaining Wall

Reinforced Retaining Wall - Intro 

This a a quick post to show some pictures of a reinforced retaining wall, along with a little non technical description, along the way.

A retaining wall is generally a wall you would build to avoid having a steep slope, or where you want to have a change in ground levels without a slope. Opting for a step instead. Retaining walls can be just a few feet high, or many meters.

Reinforced Retaining Wall - Basic Concept

If you were to stand a domino on its end, it could be easily pushed over. If however, you were to super glue the domino to a heavy table, it would a a lot harder to push over. Provided the glue were strong enough you would have to tip the table over to get the domino to topple.

In the same sense a concrete wall, can be easily pushed over by heavy soil pushing against it from one side, so we must attached the concrete wall to something heavy to stop it moving.

So we anchor the concrete block wall to a concrete slab. This is done by setting steel bars in the concrete footing, as shown above. The soil will try to push the wall, but with the weight of footing and the soil resting on top of the footing it will not move (providing the soil under the footing is not too squishy - a geotechnical investigation would determine this).

It is also important to let the ground water drain out from behind the wall. Gaps or pipes must be included to allow this.

Reinforced Retaining Wall - Case Study

In the below picture you can see the footing for the retaining wall has been cast, and the steel bars (rebar) are left poking up, ready for the wall to be attached to.

Next up the block wall is built up around the rebar. The block are hollow as they will be filled with concrete at a later date. Another option would be to build a wooden mould (shuttering) around the rebar and pour concrete in to the mould to make  wall.

As the wall is built horizontal bars are added, these are tied with thin wire to the vertical bars to keep them in place.

You can see here how the wall is built to one side of the footing. This helps keep the wall stable, as it will be loaded from (in this picture) the left hand side.

You can see more clearly here the thin wire sued to hold the bars in place prior to pouring the concrete.

On a very long wall such as this one you will need to have expansion gaps, these are breaks in the wall filled with squashy (compressible) material that allow the wall the  expand and shrink when it get hotter and colder.

Reinforced Retaining Wall - A Simple DIY Design

This retaining wall as pictured was likley designed by an engineer. And it is next to a railway so it is a very high quality, probably over specified retaining wall. 

For DIY purposes retaining walls can be built without reinforcement, from normal concrete blocks sometimes without any footings. But drainage is still very important. 

A method I have tried is a a thin strip footing topped with a concrete block wall. The blocks are laid on there side, and can be sloped gently back towards higher ground. If you do slope the wall back fill as you go. Gently pack the soil behind the wall. Every 4 or 5 block insert a length of 50mm drainage pipe between the blocks to allow of drainage. 

Wednesday, 17 January 2018

Shimano V Brake Pads / Shoes / Blocks Compared

Shimano V Brake Pads / Shoes / Blocks Compared - Intro

Shimano make  V Brake Pads / Shoes / Blocks with a number of different compounds. This compound can be softer of harder for example to suite different rim types. Each Pad / Shoe / Block, has its own model number so you can find out which you prefer.

Shimano V Brake Pads / Shoes / Blocks Compared - Threaded 

The Below Pads have a Threaded Fitting


70mm - Threaded Type - Performs especially well in wet conditions and may pass DIN standards. Gives off less noise, but the pad is heavier, faster rim wear and tends to fade.

M70T4 & M70W

70mm  - Threaded Type - Only for side wall machined rims. Performs especially well in wet conditions and may pass DIN standard. Tend to be low noise, low rim wear and fade.

S70T & S65T

60mm or 70mm - Performs well in dry conditions and tends to be low noise. Wears in muddy conditions

Shimano V Brake Pads / Shoes / Blocks Compared  - Un-Threaded

The below pads have an UN-Threaded Fitting


70mm - Performs especially well in wet conditions and may pass DIN standards. Gives off less noise, but the pad is heavier, faster rim wear and tends to fade.

M65T & M55T

65mm & 55mm - Un-Threaded - Performs especially well in wet conditions and may pass DIN standards. Faster rim wear and tends to fade.

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Tuesday, 9 January 2018

Top 5 Class D Amplifier Boards

Top 5 Class D Amplifier Boards - Intro

This page title should also have "low cost" added. All of the below boards cost less than £8 / $10, so make for a very low cost project, just be aware you will need to power these boards, and for the louder options below this can cost 2 or 3 times the cost of the board itself.

The below descriptions are boards I have owned and tried. All chips (8403, 8610 etc.) will behave differently depending on the boards used. For example if a specification says 24V, but you board has 22v capacitors, then you will not be able to run the max voltage.

Also just because a board has more capacitors and knobs on it does not mean the chip will be louder or better. The best results I find come from the most simple boards.

Top 5 Class D Amplifier Boards - 1 - PAM8403

Cost: £1 / $2
Voltage: 2.5V to 5V
Output: 2 x 3W

The top slot goes to the the PAM8403, this is the size of a postage stamp, and you can run it from a USB power supply, or 3 x AA batteries or a single lithium cell.

Its power is rated at 3W, but it is incredibly efficient, producing a room full of sound, when using 4ohm speakers.

My favorite class d amplifier, fiddly but fiesty!

If you have an old hi-fi speaker of any sort hanging around you could convert it to an active speaker, for perhaps just £2 / $4.

I have placed this board at number 1, because it is:

  • A versatile low cost amplifier
  • Very easy to power
  • Very very efficient
  • Good quality sound at all volumes
  • A lot of volume when considering low cost of board and power supply. 
Note: You can not run 1 speaker from this amplifier, both of the outputs have to be used to avoid damage to the chip. I have run a tweeter from left and woofer from right to get around this which is OK.

Top 5 Class D Amplifier Boards - 2 - PAM8610

Cost: £2 / $4
Voltage: 8V to 15V
Output: 2 x 15W

Second place, but only just. 

The PAM8610 is the logical step up from the PAM8403, it requires a higher voltage to work, and the low volume sound quality is not overly good, but it produces a very high volume for such a small amplifier. Get the basic board if you are buying with no heatsink or volume control, you do not need one. 

These is s light deterioration in sound quality at low volumes which some might find annoying. This can be well powered from 8 x AA batteries, or a cheap 12V wall socket transformer.  If you are running this amplifier from a SLA or Car Battery be a bit careful, because these sometime creep over 15V with some chargers. 

Top 5 Class D Amplifier Boards - 3 - TPA3116 

Cost: £5 / $10
Voltage: 8V to 24V
Output: 2 x 50W (Official) 2 x 15W (Real World)

This amplifier is comparable in output to the PAM8610, the sound is a lot cleaner to. But this is offset by the difficultly in proving 24V to power it adequately, it will work from 8V but you will have very low power levels until you reach 18V upwards.

I tried a complex 3 channel board, perhaps give a simple one a go.

That being said this is a versatile amplifier that will run on a very wide voltage range. The sound is crisp and clear at all volume levels, although high volume sound will be distorted if you are using an under powered supply. 

I used a 3 channel variant of this board which is so say 50 + 50 +100W, but is no where near this loud. Perhaps the board which uses NE5532 pre amplifiers. And the gain is fairly low.

Top 5 Class D Amplifier Boards - 4 - TDA2030

Cost: £3 / $6
Voltage: 8V to 16V - Will go higher on some boards. 
Output: 2 x 50W (Official) 2 x 15W (Real World)

This is actually a AB class amplifier, which is fairly inefficient. However it is small and cheap and reasonably easy to power. The sound is far richer than any of the above amplifiers, with a warm sound many will fine pleasant. 

It is not great for running from AA batteries but will run well from an SLA battery. It cannot be run from AA batteries as the power requirement is to high. 

Top 5 Class D Amplifier Boards - 5 - OEP3W or XTP8871

Cost: £1 / $2
Voltage: 2.5V to 5V 
Output: 3W Mono / 5 W Mono

I couldn't quite decide between these two they are both excellent boards that they can be powered from a USB port, requiring only 1A of power. Mono is easily achieved my mash together the positive and negative input wire. You then one have to find one speaker to use these amps, which lowers the costs still further. 

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