This article outlines potential hardware issues, their causes and how to troubleshoot them.
Overview
Running into V-Ray rendering issues may not always indicate a software problem. There are cases where hardware components can malfunction and cause instability or a defect.
This article provides answers to questions like:
- Can overheat cause rendering errors?
- How to check if my CPU overheats?
- Can overclock lead to rendering issues?
- Can hardware defects cause rendering errors?
- How to determine if a hardware component is faulty?
- How to diagnose computer hardware?
For additional information on how V-Ray utilizes computer hardware, see this article.
Overheating
A hardware component that exceeds normal workload temperature can cause system instability, which in turn can result in rendering issues. Overheating symptoms may include:
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Software crashing
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Error messages
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Hanging
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Blue screen errors
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Unexpected system shutdown
CPU or GPU overheating can potentially cause V-Ray errors.
Third-party system monitoring tools (e.g. HWMonitor, Speccy, Real Temp) can be used to do temperature readings and compare the data to the standard workload temperature specified by the manufacturer or public user reports. If the temperature exceeds these standards, overheating needs to be resolved prior to further testing.
Example Investigation
- Download and install a temperature monitoring application (e.g. HWMonitor);
- Start the software and observe the temperature readings.
Idle CPU core temperature measurements
Working CPU core temperature measurements
3. Compare the data to the manufacturer’s specifications or public user reports.
Maximum temperature allowed by the processor Integrated Heat Spreader for Intel Core i7-4790.
Note that this value is not the maximum temperature per core, as cores' temperatures vary.
A single loaded core may have high temperature values, but lower temperature in the rest of
the cores compensates for the overall CPU temperature.
Overclocking
Pushing the limits of the CPU clock may increase the performance but at the expense of heat and sometimes system stability. An overclocked CPU may cause issues, such as:
- Calculation errors
- Rendering artifacts
- Crashes
- Blue screen errors
- Hanging
Chaos Group does not recommend overclocking computer systems, since this may lead to
instability and can potentially hinder the rendering process. If your system is overclocked
and an issue arises, the first thing to do is to return the clock speed and voltage to their
standard rates before resuming the troubleshooting.
Example BIOS Reset Procedure
- Restart your computer
-
At the boot screen (before the operating system loads), press the BIOS menu key (depending on the motherboard manufacturer). Usually, it is one of the following keys:
- “Esc”
- “Del”
- “F2”
- “F8”
- “F12”
-
Locate the option to reset the BIOS settings. This is commonly found under one of the following options:
- Load Default
- Load Fail-Safe Defaults
- Load BIOS Defaults
- Load Default Settings
- Load Setup Default
- Get Default Values
- Save the changes
- Exit BIOS
Insufficient Power Supply
Rendering pushes the system's capabilities to their limit. A heavy workload requires a stable energy input from the power supply unit (PSU). Potential symptoms of power supply issues may include:
- Random system restarts
- Hanging
- Blue screen errors
- Crashes
- Screen dots, lines, or flashes
Make sure the output capacity of your PSU is enough to power all system components for heavy workloads. There are power supply calculators available online that can help approximate the power supply’s wattage required for the system.
Faulty Hardware
Purchasing brand new parts does not necessarily mean they will perform without issues. It is possible that a component is defective. Symptoms vary widely:
|
Memory (RAM)
|
Graphics Card (GPU)
|
Motherboard
|
Power Supply (PSU)
|
|---|---|---|---|
|
|
|
|
| Hard Drive (HDD) | Graphics Card (GPU) | Solid State Drive (SSD) | |
|
|
|
When rendering, malfunctioning hardware may cause instability and produce errors. In such cases, it is recommended to perform benchmarks and stress tests to determine if a component is faulty.
Benchmark tools like V-Ray Benchmark and Corona Benchmark are a good start for CPU and GPU performance tests.
For memory (RAM), CPU and GPU stress tests, there is a number of free tools available on the Internet. For example: Prime95 (CPU), Cinebench (CPU), Heaven Benchmark (GPU), FurMark (GPU), MemTest86 (Memory).
Example Investigation
- Download and install a stress-testing application depending on the component (e.g. Prime95).
2. Start the software and choose a stress test.
3. A work log opens for each logical CPU that updates the information about the test.
4. If one or more threads fail the workers will stop with a fatal error message for the thread.
5. Test up to 3 hours, unless errors occur sooner. Monitor the component’s temperature while testing to ensure safety. You can manually stop the test from Test > Stop.
6. If no errors occur the logs will look similar to this:
Incompatible Components
A variety of hardware components are available for purchase, but some may not be compatible when combined. This may also include combining new and old parts mixed in the same system.
Make sure all of your system’s components are compatible with each other. Online hardware assembly tables (e.g. pcpartpicker.com) have compatibility filters that detect conflicting components. To further validate compatibility, inspect the component's requirements and compatibility listed by the manufacturer.
Conclusion
Although the software is what we interact with, it is the hardware that does the work. These troubleshooting methods can help determine if an issue is the result of a hardware failure. A well-functioning hardware system will provide smooth-running software that performs the selected task from start to finish.